U.S. patent number 4,946,380 [Application Number 07/359,086] was granted by the patent office on 1990-08-07 for artificial dexterous hand.
This patent grant is currently assigned to University of Southern California. Invention is credited to Sukhan Lee.
United States Patent |
4,946,380 |
Lee |
August 7, 1990 |
**Please see images for:
( Certificate of Correction ) ** |
Artificial dexterous hand
Abstract
An artificial dexterous hand is provided for conformally
engaging and manipulating objects. The hand includes an articulated
digit which is connected to an engagement sub-assembly and has a
first shape adaption mechanism associated with it. The digit has a
digit base and first and second phalanges. The digit base is
operatively interconnected to the first phalange by a base joint
having a base pulley. The phalanges are operatively interconnected
by a separate first phalange joint having a first phalange pulley.
The engagement sub-assembly includes a tendon, which is received by
the base pulley and by the first phalange pulley, and an actuation
device for selectively tensioning the tendon. The first shape
adaption mechanism is responsive to and receives the tendon. It is
also situated between the base joint and the first phalange joint
and is connected to the first phalange. Upon actuation by the
actuation device, the phalanges are caused to pivot relative to the
base joint and the second phalange is caused to pivot relative to
the first phalange. At the same time, the first shape adaption
mechanism controls the sequence of the aforementioned pivoting of
the phalanges through application of braking force to the
tendon.
Inventors: |
Lee; Sukhan (La Canada,
CA) |
Assignee: |
University of Southern
California (Los Angeles, CA)
|
Family
ID: |
27000329 |
Appl.
No.: |
07/359,086 |
Filed: |
May 30, 1989 |
Current U.S.
Class: |
623/24; 623/64;
294/111; 901/21 |
Current CPC
Class: |
B25J
15/0009 (20130101); A61F 2/583 (20130101); A61F
2002/5069 (20130101); A61F 2002/30525 (20130101); A61F
2002/587 (20130101); A61F 2002/701 (20130101); A61F
2/70 (20130101); A61F 2220/0025 (20130101); A61F
2/586 (20130101); A61F 2002/704 (20130101); A61F
2002/30523 (20130101) |
Current International
Class: |
B25J
15/00 (20060101); A61F 2/68 (20060101); A61F
2/58 (20060101); A61F 2/50 (20060101); A61F
2/00 (20060101); A61F 2/70 (20060101); A61F
002/68 () |
Field of
Search: |
;623/21-24,57,64
;901/21,38,39 ;294/111,106 |
References Cited
[Referenced By]
U.S. Patent Documents
Foreign Patent Documents
|
|
|
|
|
|
|
488696 |
|
Feb 1976 |
|
SU |
|
2175877A |
|
Dec 1986 |
|
GB |
|
Other References
Los Angeles Times, May 29, 1988, "Odetics to Build a 3-Fingered
Robotic Hand for Pentagon Research Agency". .
"Studies on a Vertsatile Handling System Having Multijoined
Fingers", Tokuji Okada, Researches of the Electrotechnical
Laboratory, Jul. 1982. .
"Design and Construction of a Five-Fingered Robotic Hand", M.
Caporali and M. Shahinpoor, Robotics Age, Feb. 1984..
|
Primary Examiner: Apley; Richard J.
Assistant Examiner: Cheng; Joe H.
Attorney, Agent or Firm: Pretty, Schroeder, Brueggemann
& Clark
Government Interests
This invention was made with government support under contract no.
956501 awarded by the California Institute of Technology, Jet
Propulsion Laboratory to the University of Sourthern California.
This contract is a subcontract under NASA contract NAS7-918. The
United States Government has certain rights in the invention.
Claims
I claim:
1. An artificial dexterous hand for conformably engaging and
manipulating objects, comprising:
an articulated digit having a digit base and first and second
phalanges, said digit base being operatively interconnected to said
first phalange by a base joint having a base pulley, said phalanges
being operatively interconnected by a separate first phalange joint
having a first phalange pulley; and
engagement sub-assembly means for causing said phalanges to pivot
relative to said base joint and for causing said second phalange to
pivot relative to said first phalange, said engagement sub-assembly
means including,
a tendon received by said base pulley and by said first phalange
pulley,
actuation means for selectively tensioning said tendon, and
first shape adaption means, responsive to and receiving said
tendon, for controlling the sequence of pivoting of said phalanges
through application of braking force to said tendon, said first
shape adaption means being located between said base joint and said
first phalange joint and being connected to said first
phalange.
2. An artificial dexterous hand according to claim 1, wherein the
braking force exerted by said first shape adaption means increases
as said tendon is increasingly tensioned.
3. An artificial dexterous hand according to claim 1, wherein said
first shape adaption means includes:
a first brake rod connected to said first phalange and having a
series of first external threads;
a first brake pulley operatively disposed around said first brake
rod and received by said tendon, and
first braking means, engageable with said first external threads
and contactable with said first brake pulley, for selectively
regulating the movement of said first brake pulley through
application of braking force to said first brake pulley in response
to tension exerted by said tendon on said first brake pulley.
4. An artificial dexterous hand according to claim 3, wherein said
first external threads define a triple-threaded screw type thread
pattern.
5. An artificial dexterous hand according to claim 3, wherein said
first braking means regulates the movement of said first brake
pulley by applying increasing braking force as increased tension is
exerted by said tendon on said brake pulley.
6. An artificial dexterous hand according to claim 3, wherein said
first braking means includes:
a first brake disc disposed around said first brake rod and
engageable with said first external threads, said first brake disc
having a first brake arm;
first arm means, connected to said first brake arm, for receiving
said tendon; and
biasing means, secured to said first brake arm and to said first
phalange for providing said first brake disc with a threshold
braking force.
7. An artificial dexterous hand according to claim 6, wherein said
first braking means further includes means, connected to said first
brake pulley, for securing said tendon to said first brake
pulley.
8. An artificial dexterous hand according to claim 6, wherein:
said first braking means further includes
a first secondary brake rod connected to said first phalange,
a first friction plate slidably connected to said first secondary
rod and disposed between said first brake disc and said first brake
pulley, said first plate further being movable along said first
brake rod in response to actuation from said first brake disc;
and
said first brake pulley includes a friction pad facing said first
friction plate.
9. An artificial dexterous hand according to claim 6, wherein said
first braking means further includes,
a first substantially dish-shaped washer disposed around said first
brake rod and located between said first brake pulley and said
first brake disc, said first washer being movable along said first
brake rod in response to actuation from said first brake disc.
10. An artificial dexterous hand according to claim 1, wherein said
first shape adaption means includes:
a first brake rod connected to said first phalange;
a first brake pulley operatively disposed around said first brake
rod and received by said tendon; and
first braking means, contactable with said first brake pulley, for
selectively regulating the movement of said first brake pulley
through application of braking force to said first brake pulley in
response to tension exerted by said tendon on said first brake
pulley.
11. An artificial dexterous hand according to claim 10, wherein
said first braking means regulates the movement of said first brake
pulley by applying increasing braking force as increased tension is
exerted by said tendon on said first brake pulley.
12. An artificial dexterous hand according to claim 10, wherein
said first braking means includes:
a secondary brake rod secured to said first phalange;
a first brake arm having a first end and a second end, with said
first end of said first brake arm being pivotally secured to said
secondary brake rod near one end of said secondary brake rod;
first arm means, connected to said first brake arm near the second
end of said first brake arm, for receiving said tendon;
a first brake member having a concave outer surface that is
engageable with the outer surface of said first brake pulley, said
first brake member being secured to said first brake arm; and
a first biasing element having a first biasing end and a second
biasing end, with the first biasing end of said first biasing
element being secured to the second end of said first brake arm and
the second biasing end of said first biasing element being secured
to said first phalange.
13. An artificial dexterous hand according to claim 1, further
including:
a second articulated digit having a second digit base and third and
fourth phalanges, said second digit base being operatively
interconnected to said third phalange by a second base joint having
a second base pulley, said third and fourth phalanges being
operatively interconnected by a separate second phalange joint
having a second phalange pulley; and
second engagement sub-assembly means for causing said third and
fourth phalanges to pivot relative to said second base joint and
for causing said fourth phalange to pivot relative to said third
phalange, said second engagement sub-assembly means including,
a second tendon received by said second base pulley and by said
second phalange pulley, and
second actuation means for selectively tensioning said tendon.
14. An artificial dexterous hand for conformally engaging and
manipulating objects, comprising:
an articulated digit having a digit base and at least three
phalanges with any successive two of said phalanges being
interconnected by a separate one of a plurality of phalange joints
and with one of said phalanges being interconnected to said digit
base by a base joint, each of said phalange joints having a
phalange pulley and said base joint having a base pulley; and
engagement sub-assembly means for causing said phalanges to pivot
relative to said base joint and for causing said phalanges to pivot
relative to each other, said engagement sub-assembly means
including,
a tendon received by said base pulley and by said phalange
pulleys,
actuation means for selectively tensioning said tendon; and
a plurality of shape adaption means, responsive to and receiving
said tendon, for controlling the sequence of pivoting of said
phalanges through application of braking force to said tendon, with
a separate one of said shape adaption means being located between
each of said joints and being connected to said digit.
15. An artificial dexterous hand according to claim 14, wherein the
braking force exerted by each of said shape adaption means
increases as said tendon is increasingly tensioned.
16. An artificial dexterous hand according to claim 14, wherein
each of said shape adaption means includes:
a first brake rod connected to its respective phalange and having a
series of first external threads;
a first brake pulley operatively disposed around said first brake
rod and received by said tendon, and
first braking means, engageable with said first external threads
and contactable with said first brake pulley, for selectively
regulating the movement of said first brake pulley through
application of braking force to said first brake pulley in response
to tension exerted by said tendon on said first brake pulley.
17. An artificial dexterous hand according to claim 16, wherein
said first external threads contained within each of said shape
adaption means define a triple threaded screw type thread
pattern.
18. An artificial dexterous hand according to claim 16, wherein
said first braking means contained within each of said shape
adaption means regulates the movement of said first brake pulley by
applying increasing braking force as increased tension is exerted
by said tendon on said first brake pulley.
19. An artificial dexterous hand according to claim 16, wherein
said first braking means contained within each of said shape
adaption means includes:
a first brake disc disposed around said first brake rod and
engageable with said first external threads, said first brake disc
having a first brake arm;
a first arm means, connected to said first brake arm, for receiving
said tendon; and
biasing means, secured to said first brake arm and to its
respective phalange, for providing said first disc with a threshold
braking force.
20. An artificial dexterous hand according to claim 19, wherein
said first braking means contained within each of said shape
adaption means further includes means, connected to said first
brake pulley, for securing said tendon to said first brake
pulley.
21. An artificial dexterous hand according to claim 16,
wherein:
said first braking means contained within each of said shape
adaption means further includes
a first secondary brake rod connected to its respective
phalange,
a first friction plate slidably connected to said first secondary
brake rod and disposed between said first braking means and said
first brake pulley, said first friction plate further being movable
along said first brake rod in response to actuation from said first
braking means; and
said first brake pulley includes a friction pad facing said first
friction plate.
22. An artificial dexterous hand according to claim 16, wherein
said first braking means contained within each of said shape
adaption means further includes a first substantially dish-shaped
washer disposed around said first brake rod and located between
said first brake pulley and said first braking means, said first
washer being movable along said first brake rod in response to
actuation from said first braking means.
23. An artificial dexterous hand according to claim 14, wherein
each of said shape adaption means includes:
a first brake rod connected to its respective phalange;
a first brake pulley operatively disposed around said first brake
rod and received by said tendon; and
first braking means, contactable with said first brake pulley, for
selectively regulating the movement of said first brake pulley
through application of braking force to said first brake pulley in
response to tension exerted by said tendon on said first brake
pulley.
24. An artificial dexterous hand according to claim 23, wherein
said first braking means contained within each of said shape
adaption means regulates the movement of said first brake pulley by
applying increasing braking force as increased tension is exerted
by said tendon on said first brake pulley.
25. An artificial dexterous hand according to claim 23, wherein
said first braking means contained within each of said shape
adaption means includes:
a secondary brake rod secured to its respective phalange;
a first brake are having a first end and a second end, with said
first end of said first brake arm being pivotally secured to said
secondary brake rod near one end of said secondary brake rod;
first arm means, connected to said first brake arm near the second
end of said first brake arm, for receiving said tendon;
a first brake member having a concave outer surface that is
engageable with the outer surface of said first brake pulley, said
first brake member being secured to said first brake arm; and
a first biasing element having a first biasing end and a second
biasing end, with the first biasing end of said first biasing
element being secured to the second end of said first brake arm and
the second biasing end of said first biasing element being secured
to its respective phalange.
26. An artificial dexterous hand according to claim 14, further
including:
a second articulated digit having a second digit base and fourth,
fifth and sixth phalanges, said second digit base being operatively
interconnected to said fourth phalange by a second base joint
having a second base pulley, said fourth and fifth phalanges being
operatively interconnected by a separate third phalange joint
having a third phalange pulley and said fifth and sixth phalanges
being operatively interconnected by a separate fourth phalange
joint having a fourth phalange pulley; and
second engagement sub-assembly means for causing said fourth, fifth
and sixth phalanges to pivot relative to said second base joint and
for causing said fifth phalange to pivot relative to said fourth
phalange and said sixth phalange to pivot relative to said fifth
phalange, said second engagement sub-assembly means including,
a second tendon received by said second base pulley and by said
third and fourth phalange pulleys, and
second actuation means for selectively tensioning said tendon.
Description
BACKGROUND OF THE INVENTION
This invention relates generally to artificial hands and, more
particularly, to an artificial dexterous hand having one or more
articulated digits that can be versatilely configured so as to more
easily adapt to differently shaped objects.
A variety of artificial hands are known and have widespread
applications in many diverse fields, such as prosthetics, space or
undersea exploration and the like. Industrial applications for
artificial hands also abound. The existence of these and other
applications has created an increasing need for artificial hands to
reliably perform many complex or delicate tasks, particularly in
certain work environments that may be innately unsuitable for task
completion with the aid of an artificial hand. This need has in
turn give rise to an accompanying need for artificial hands which
are capable of assuming more configurations and more versatilely
adapting to various work environments and to various shapes of
objects.
For the purpose of allowing artificial hands to assume various
configurations, artificial hands typically have articulated digits.
Each digit commonly has a number of phalanges which are usually
separate mechanical linkages. Each successive two phalanges are in
turn interconnected by one of a series of joints which permit the
phalanges to pivot or pitch relative to each other. Some joints
have a series of gears for accomplishing relative pivoting or
pitching of two successive phalanges. Still other joints may have
pulleys which are each interconnected by a tendon or wire that is
received by each pulley. In this case, the application of tensile
force to the tendon causes each pulley to rotate and, thereby,
pivot or pitch the phalanges relative to each other.
These known construction of joints, tend, however, to have
fundamental disadvantages. A gear construction for the joints may
result in an unduly heavy digit which can require a rather
expensive assemblage of actuation mechanisms for operation of the
hand. A gear construction can also create an artificial hand which
is overly rigid or jaw-like in its movements. On the other hand,
the aforementioned pulley and tendon construction may result in a
digit which is too flexible and tends to easily become unstable.
Moreover, both types of constructions tend to cause the phalanges
of the digit to pivot arbitrarily, unless their pivoting is
controlled by a complex and costly assemblage of actuation and
control mechanisms associated with each joint.
Further, the digits of certain existing hands tend to be unstable
during pivoting and to inadequately compensate for the effects of
forces that develop near the outer or fingertip joint during the
grasping or manipulation of an object by the hand. That is, the
outer joints of a digit tends to experience greater forces than the
other joints of the digit. These forces tends to undesirably
propagate from the outer joint to the other joints such that the
finger becomes unstable and may be unable to retain its desired
configuration. Some efforts to address this problem employ separate
motors to attempt to control the pivoting at each joint. This is,
however, costly and requires a cumbersome assemblage of actuation
mechanisms and complex control systems.
The nature of certain tasks and the inherent characteristics of
certain work environments also require the digits of the hand to
perform complex or delicate tasks without undue delay. Existing
digits tend to be unable to suitably conform their pivoting or
pitching configurations in a relatively short period of time.
Moreover, existing digits also tend to be unable to versatilely
alternate between robust and delicate modes of grasping and
manipulation without expensive control mechanisms.
It should, therefore, be appreciated that there has existed a
definite need for an artificial dexterous hand having one or more
digits that are better capable of versatilely adapting their
respective configurations to conform to various shapes of objects
and which are constructed in a manner more conducive to digit
stability and efficient control of the sequence of pivoting of the
phalanges corresponding to each digit.
SUMMARY OF THE INVENTION
The present invention, which addresses the aforementioned need, is
embodied in an artificial hand which can versatilely adapt its
configuration to differently shaped objects and which is more
stable during operation. The hand includes an articulated digit
which is operatively connected to an engagement sub-assembly and
has a first shape adaption mechanism associated with it. The digit
has a digit base and first and second phalanges. The digit base is
operatively interconnected to the first phalange by a base joint
having a base pulley. The first and second phalanges are
operatively interconnected by a separate first phalange joint
having a first phalange pulley. The engagement sub-assembly
includes a tendon, which is received by the base pulley and by the
first phalange pulley, and an actuation device for selectively
tensioning the tendon.
The first shape adaption mechanism is responsive to and receives
the tendon. It is also situated between the base joint and the
first phalange joint and is connected to the first phalange. When
the actuation device increasingly tensions the tendon, the
resulting tensile force propagates the base joint and to the first
shape adaption mechanism. At the same time, the first shape
adaption mechanism selectively applies increasing braking force to
the tendon. This force restrains the second phalange from pivoting
relative to the first phalange by impeding the propagation of
sufficient tensile force to the first phalange joint. At the same
time, the first shape adaption mechanism permits the first and
second phalanges to pivot together relative to the base joint. The
first shape adaption mechanisms also selectively permits the
aforementioned relative pivoting of the first and second phalanges
when the tensile force has exceeded the maximum sustainable braking
force. The shape adaption mechanism thus selectively controls the
sequence of the pivoting of the phalanges and ensures that the
digit and its constituent phalanges retain their stability during
operation and, particularly, during pivoting.
The digit can also have three or more interconnected phalanges. In
that event, there is a corresponding increase in phalange joints
and an additional shape adaption mechanism is advantageously
located between each successive pair of phalange joints. Each
additional shape adaption mechanism then functions similarly to the
first shape adaption mechanism.
In one preferred form of the invention, the first shape adaption
mechanism includes a first brake pulley and a first brake which are
each operatively disposed around a first brake rod. The first brake
pulley is received by the tendon and has a first friction pad
secured to its interradial surface, while the first brake rod has a
series of first external threads which can define a triple threaded
screw type thread pattern. The first brake is engageable with the
first external threads and is contactable with the first brake
pulley. It selectively regulates the movement of the first brake
pulley by applying increasing braking force to the first brake
pulley in response to increased tension exerted by the tendon on
the first brake pulley.
In more detailed aspects of the aforementioned preferred form of
the invention, the first brake includes a first brake disc which is
disposed around the first brake rod and which is engageable with
the first external threads. The first brake disc also has a first
brake arm which has a first arm roller connected to it. The first
arm roller receives the tendon which in turn exerts force on the
first arm roller when the tendon is tensioned. A suitable biasing
element is also secured to the first brake arm and to the first
phalange in order to provide the first brake disc with a threshold
braking force against the first brake pulley. Additionally, the
first brake has a suitable mechanism, which is connected to the
first brake pulley, for securing the tendons in the first brake
pulley.
In still more detailed aspects of the aforementioned preferred form
of the invention, the first brake includes a first secondary brake
rod, which is connected to the first phalange, and a first friction
plate that is slidably connected to the first secondary rod. The
first friction plate is also disposed between the first brake disc
and the first brake pulley and is movable along with the first
brake rod in response to actuation from the first brake disc.
In accordance with an alternative form of the invention, the first
shape adaption mechanism is similar to the aforementioned preferred
form, except that the friction plate and first secondary rod are
replaced with a substantially dish-shaped washer. The dish-shaped
washer is disposed around the first brake rod and is located
between the first brake pulley and the first brake disc. It is
further movable along with the first brake rod in response to
actuation from the first brake disc.
In a further alternative form of the invention, the first shape
adaption mechanism includes a first brake pulley which is
operatively disposed around a first brake rod and which is
engageable with a first brake. The first brake pulley is received
by the tendon, while the first brake rod is connected to the first
phalange. The first brake is contactable with the first brake
pulley and selectively regulates the movement of the first brake
pulley through application of increasing braking force to the first
brake pulley in response to increasing tension exerted by the
tendon on the first brake pulley.
The first brake of the immediately aforementioned alternative form
includes a first brake arm which is pivotally secured to a
secondary brake rod near one end of the secondary brake rod and on
the other end has a first arm rod connected to it. The secondary
brake rod is secured to the first phalange, while the first arm rod
receives the tendon. Moreover, the first brake includes a first
brake member that cooperates with a first biasing element for the
purpose of applying both threshold and increasing braking force to
the first brake pulley. The first brake member has a concave outer
surface which is engageable with the outer surface of the first
brake pulley and is secured to the first brake arm. The first
biasing element is secured to one end of the first brake arm and on
its other end to the first phalange.
In applications where more than one shape adaption mechanism is
employed in the digit, each additional mechanism would be
constructed similarly to the particular form of the invention that
is used for its companion first shape adaption mechanism. Each
additional mechanism would, however, preferably be secured to a
separate successive phalange. Thus, in the case of two shape
adaption mechanisms, the first mechanism would be secured to the
first phalange and the second mechanism would be secured to the
second phalange.
Other features and advantages of the present invention will become
more apparent from the following detailed description, taken in
conjunction with the accompanying drawings, which illustrate, by
way of example, the principles of the invention.
BRIEF DESCRIPTION OF THE DRAWINGS
The accompanying drawings illustrate the invention. In such
drawings:
FIG. 1 is a perspective view of the artificial dexterous hand of
the present invention associated with an accompanying control
system and shown grasping a sphere.
FIG. 2 is a fragmentary perspective view of the artificial
dexterous hand of FIG. 1 illustrating the respective configurations
of the digits of the hand in their respective fully extended or
rest positions and further illustrating the center finger and right
thumb engagement sub-assemblies.
FIG. 3 is a simplified and somewhat enlarged perspective view of
the engagement assembly of the artificial dexterous hand of the
present invention.
FIG. 4 is an enlarged transverse sectional view of the left thumb
of the hand, taken substantially along lines 4--4 of FIG. 2, and
illustrating one preferred embodiment of the shape adaption
mechanism of the present invention.
FIG. 5 is an enlarged schematic representation of the interior of
the left thumb illustrated in FIG. 4.
FIG. 6 is an enlarged fragmentary, transverse sectional view of an
alternative embodiment of shape adaption mechanism situated within
the interior of the left thumb.
FIG. 7 is an enlarged side view of still another alternative
embodiment of shape adaption mechanism.
FIG. 8 is an enlarged schematic representation of the interior of
the left thumb illustrating the alternative shape adaption
mechanism embodiment of FIG. 7.
FIG. 9 is an enlarged top view of the artificial dexterous hand of
the present invention hand with selected features illustrated by
way of cut-away views.
FIG. 10 is an enlarged, fragmentary top view of the left thumb and
portions of the left thumb and right thumb and finger engagement
sub-assembly with selected features illustrated by way of cut-away
views.
FIG. 11 is an enlarged fragmentary, side elevational view of the
left thumb and portions of the left thumb engagement sub-assemblies
with certain features illustrated by way of cut-away views.
FIG. 12 is an enlarged, fragmentary bottom view of a portion of the
right thumb engagement sub-assembly with selected features
illustrated by way of cut-away views
FIG. 13 is an enlarged fragmentary, side elevational view of the
finger and portions of the finger engagement sub-assembly with
selected features illustrated by way of cut-away views.
FIG. 14 is an enlarged fragmentary, side elevational view of the
right thumb and selected portions of the left thumb, right thumb
and finger engagement assemblies with selected features illustrated
by way of cut-away views.
FIG. 15 is a schematic representation showing the control system of
FIG. 1 and its interaction with the hand.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
With reference now to the drawings, and particularly to FIG. 1,
there is shown an artificial dexterous hand 10 for grasping and
manipulating objects, such as a sphere 12, in accordance with the
present invention. The hand 10 includes a center finger or finger
digit 14, which is interposed between left and right thumbs or
thumb digits 16 and 18, and a hand engagement assembly 20 that is
operatively connected to the finger or finger digit 14 and thumbs
or thumb digits 16 and 18. The engagement assembly 20 contains left
and right thumb engagement subassemblies 22 and 24 and a finger
engagement sub-assembly 26 which are clustered together so as to
economize on space and allow the hand 10 to operate in more
confined environments. (See FIGS. 1-2, 15.) The engagement assembly
20 is also secured to a suitable support structure 28 and connected
to an appropriate control system 30. (See FIGS. 1 and 15.) The
support structure 28 lends stability to the engagement assembly 20
and to the finger 14 and thumbs 16 and 18 during operation of the
hand 10. The control system 30 is linked to the engagement assembly
20 by a control cable 32 that contains suitable wiring and is
received by an aperture 33 in the support structure 28. The control
system 30 permits selective and sensitive regulation of the
respective movements of the finger 14 and thumbs 16 and 18.
The present invention provides an artificial dexterous hand 10
having articulated digits that can be versatilely configured so as
to more easily adapt to differently shaped objects in many
different work environments. The digits of the hand 10 are each
constructed in a manner that tends to make each digit more stable
during operation and permits efficient and effective control of the
pivoting of each digit along its associated articulated areas. The
hand 10, therefore, tends to have a significant degree of
kinesthetic perception and to more properly perform tasks that may
require it to alternate between robust and delicate modes of
grasping and manipulation. The aforementioned features also tend to
diminish the complexity, cost and size of the hand 10 and
particularly, to reduce the complexity of the engagement assembly
that would otherwise be necessary. At the same time, the lesser
degree of complexity, and the decreased size and cost do not tend
to adversely affect the overall functional capability of the hand
10.
In accordance with one preferred form of the invention, the finger
14, thumbs 16 and 18 and the engagement assembly 20 are constructed
in a manner that permits the hand 10 to be configured substantially
like a human left hand, a human right hand, an integrated form of a
human left hand and a human right hand, or three fingers of a human
hand. Thus, substantially like their human counterparts, the finger
14 and thumbs 16 and 18 have multiple degrees of freedom and the
capability to assume a wide variety of configurations in three
dimensional space. As shown in FIGS. 1-2 the left and right thumbs
16 and 18 and finger 14 are operatively connected respectively to
the left thumb sub-assembly 22, right thumb sub-assembly 24 and
finger sub-assembly 26. Each sub-assembly 22, 24 and 26, therefore,
selectively moves its corresponding digit in response to selective
commands from the control system 30.
More particularly, with reference first to the left thumb 16 and
the left thumb engagement sub-assembly 22, the left thumb 16
includes outer, middle and inner left thumb phalanges or linkages
34, 36 and 38 respectively which together are coupled to a left
thumb base or base linkage 40. (See FIGS. 1-3.) The left base
linkage 40 occupies a position somewhat similar to that occupied by
a metacarpal of a human hand. It includes an oppositely disposed
pair of somewhat knuckle shaped left links 42 and 44 that are
securely seated on a left base plate 46 that has a substantially
circular cross-section.
As more fully described below, the left base linkage 40 is
connected to the left thumb engagement subassembly 22 so as to
permit the left thumb 16 to yaw, roll and pitch or pivot relative
to three separate left thumb base axes running through the left
thumb base 40. With reference to FIG. 3(c), it will be observed
that the axis passing vertically through the left thumb base 40
corresponds to the axis relative to which the left thumb 16 yaws
(hereinafter, "left thumb base yaw axis".) The axis passing
horizontally through the left thumb base 40 is associated with
rolling of the left thumb 16 (hereinafter, "left thumb base roll
axis".) The remaining axis, which is substantially orthogonal to
the transverse axis of the left thumb 16 in its fully extended
position, is associated with pitching or pivoting of the left thumb
16. It preferably moves along with the left thumb 16 when it yaws
(hereinafter, "left thumb pitch or pivoting base axis".) The
aforementioned left thumb base axes are advantageously, but not
necessarily, substantially mutually orthogonal to each other. Thus,
when the position of the left thumb 16 corresponds to the fully
extended or rest position of the left right thumb 16 shown in FIG.
2, the left thumb base axes will be mutually orthogonal. On the
other hand, where the left thumb 16 has yawed into the position
shown in FIG. 3(c) and, thereby, carried the left thumb base pitch
axis through a similar yaw angle, the left thumb base roll and
pitch axes will no longer be mutually orthogonal.
Each of the left thumb phalanges 34, 36 and 38 is hollow and bears
some resemblance in size and shape to its counterpart portion of a
human middle finger as the middle finger would appear to an
observer. As such, they together define a left thumb 16 that is
rather similar in dimensions to a human middle finger. As depicted
in FIG. 4, the outer left phalange 34 has opposing upper and lower
side linkages 48 and 50. Correspondingly, the middle left phalange
36 has opposing upper and lower side linkages 52 and 54, while the
inner left phalange has opposing upper and lower side linkages 56
and 58. The upper and lower linkages 48 and 50 are each necked down
such that they are overlapped respectively by the opposing upper
and lower side linkages 52 and 54 of the middle left phalange 36.
So too with the opposing side linkages 52 and 54 of the middle left
phalange 36 relative to opposing side linkages 56 and 58 of the
inner left phalange 38 and with opposing side linkages 56 and 58 of
the inner left phalange 38 relative to the left links 42 and 44 of
the and left thumb base or base linkage 40.
The outer left phalange 34 can also have top crossmember 60 which
is formed integral with the sections of the upper and lower side
linkages 48 and 50 that are located farthest from the upper and
lower side linkages 52 and 54 respectively. The top member 60 is
oriented substantially orthogonal to the transverse axis of the
left thumb 16 and has an integrally formed cap screw 62 that
protrudes transversely toward the tip of the left thumb 16. (See
FIG. 4.) The cap screw 62 can then receive a somewhat domeshaped
cap 64 that makes the left thumb 16 appear more anthropomorphic and
has a contour that may facilitate grasping and manipulation of
objects.
The outer left phalange 34 further advantageously has a left tendon
pin 66 that extends axially through the outer left phalange 34 and
is secured to the upper and lower side linkages 48 and 50. It is
also located adjacent the top member 60 and is substantially
orthogonal to it. The left pin 66 can be better retained within the
outer left phalange 34 by a suitable left pin screw 68. The screw
68 is threaded into a bore in the left pin 66 and has its end
oriented substantially flush with the lower linkage 50. The left
link 42 of the left base linkage 40 can also securely receive a
left link pin 70 around which a left link pulley 72 is disposed.
The significance of the left tendon pin 66 and left link pulley 72
will become apparent during later discussion of the pitching or
pivoting of the left thumb 16. The left phalanges 34, 36 and 38 can
also be surrounded by a suitable cover to protect them from the
environment.
For the purpose of furnishing the left thumb 16 with articulated
characteristics of a human finger, the interior of the left thumb
16 has separate outer, middle, and inner or base left thumb joints
74, 76 and 78. The outer left joint 74 is essentially interposed
between the upper side linkages 48 and 52 and lower side linkages
50 and 54. Correspondingly, the middle left joint is essentially
interposed between the upper side linkages 52 and 56 and the lower
side linkages 54 and 58. Finally, the inner or base left joint is
essentially interposed between the upper side linkage 56, the left
link 42, and the lower side linkage 58 and the left link 44. The
outer left joint 74 operatively attaches the outer left phalange 34
to the middle left phalange 36, while the middle left joint 76
operatively attaches the middle left phalange 36 to the inner left
phalange 38. Correspondingly, the inner left joint 78 operatively
attaches the inner left phalange 38 and the left thumb base or base
linkage 40 to each other.
As depicted in FIG. 4, the outer left joint 74 has an outer left
pulley 80 that defines a central aperture for receiving an outer
left thumb rod 82. Suitable outer left bearings 84 are situated
within the aperture for allowing the outer left pulley to more
stably rotate relative to the outer left rod 82. The outer left rod
82 extends axially through the side linkages 52 and 54 of the
middle left phalange 36. It also defines a bore for receiving a
suitable outer left rod screw 86 that assists in retaining the
outer left rod 82. The head of the screw 86 abuts the side linkage
54 of the middle left phalange 36.
For the purpose of more snugly retaining the outer left bearing 84
and stabilizing the outer left pulley 80, the outer left joint 74
can also have a pair of outer left sleeves 88 and 90. The sleeve 88
is disposed between the pulley 80 and the side linkage 48 of the
outer left phalange 34, while the sleeve 90 is disposed between the
pulley 80 and the side linkage 50 of the outer left phalange
34.
The middle and inner left joints 76 and 78 are of similar
construction, except for some differences in the individual sizes
of the joint components that may be needed to compensate for the
differing pitching or pivoting loads experienced by the left
phalanges 34, 36 and 38 and the overall dynamics of the left thumb
16. The middle left joint 76 preferably, but not necessarily, has a
substantially contiguous pair of middle left pulleys 92 and 94 that
define a central aperture for receiving a middle left thumb rod 96.
Suitable middle left bearings 98 are situated within the aperture
for allowing the middle left pulleys 92 and 94 to more stably
rotate relative to the middle left rod 96. The middle left rod 96
extends axially through the side linkages 56 and 58 of the inner
left phalange 38. It also defines a bore for receiving a suitable
middle left rod screw 100 that assists in retaining the middle left
rod 96. The head of the screw 100 abuts the side linkage 58 of the
inner left phalange 38.
A middle washer 102 can be disposed about the middle left rod 96
and adjacent to the side linkage 52 of the middle left phalange 36
in order to prevent undue axial movement of the middle left pulleys
92 and 94. The snugness of the fit of the bearings 98 and the
stability of the middle left pulleys 92 and 94 can also be
augmented by disposing a pair of middle sleeves 104 and 106 about
the middle left rod 96. When so disposed, the sleeve 104 is located
between each of the middle left pulleys 92 and 94 and the sleeve
106 is located adjacent the side linkage 54 of the middle left
phalange 36.
In like manner, the inner left joint 78 preferably, but not
necessarily, has a substantially contiguous pair of inner left
pulleys 108 and 110 that define a central aperture for receiving an
inner left thumb rod 112. Suitable inner left bearings 114 are
situated within the aperture for allowing the inner left pulleys
108 and 110 to more stably rotate relative to the inner left rod
112. The inner left rod 112 extends axially through the left links
42 and 44. It also defines a bore for receiving a suitable inner
left rod screw 116 that assists in retaining the rod 112 within the
links 42 and 44 of the left thumb base 40. The head of the screw
116 abuts the link 44.
Similar to the middle left joint 76, the inner left joint 78 can
also have a inner washer 118 and a pair of inner sleeves 120 and
122. The inner washer 118 is situated adjacent the upper side
linkage 56 and disposed around the inner left rod 112. The sleeves
120 and 122 are disposed around the inner left rod 112. The sleeve
120 is located between each of the inner left pulleys 108 and 110,
while sleeve 122 is located adjacent the lower side linkage 58. It
will be appreciated that the outer, middle, and inner left thumb
joints 74, 76 and 78 can be constructed in a number of other ways
that achieve relative pivoting of the left thumb phalanges 34, 36
and 38. Thus, for instance, a single pulley could be used for each
joint.
In accordance with a separate feature of the invention, the
interior of the left thumb 16 can also be provided with inner and
outer shape adaption mechanisms 130 and 132. The mechanisms 130 and
132 together control the sequence of pitching or pivoting of the
left phalanges 34, 36 and 38 relative to each other and of the left
phalanges 34, 36 and 38 relative to the left thumb base or base
linkage 40. They also allow the left thumb 16 to more versatilely
configure itself to conform to different shapes of objects More
particularly, as shown in FIG. 4, the inner shape adaption
mechanism 130 is situated between the middle and inner or base left
thumb joints 76 and 78. It includes an inner left brake pulley 134
and an inner left brake 136 which are each disposed around an inner
left brake rod 138. (See FIGS. 4-5.)
The inner brake pulley 134 is selectively rotatable in both a
clockwise and counterclockwise direction relative to the inner
brake rod 138. It has a centrally located inner bore 140 which
receives needle or other suitable bearings 142. The bearings 142
are abutable with the inner brake rod 138. They, therefore, tend to
reduce frictional forces between the inner brake rod 138 and the
inner brake pulley 134 and to facilitate proper rotation of the
pulley 134. The inner brake pulley 134 can also have a suitable
friction pad 144 affixed to its inner radial surface 146. The pad
144 faces the inner left brake 136. As will become evident below,
the pad 144 reduces wear on the inner brake pulley 134 during
operation of the inner shape adaption mechanism 130.
The inner left brake rod 138 extends axially through the interior
of the left thumb 16 and is received through bores (not shown) in
the opposing side linkages 56 and 58 of the inner left phalange 38.
It is also secured to the side linkage 56 of the inner left
phalange 38 by an appropriate set screw 148. The inner brake rod
138 further becomes tapered as it extends from the side linkage 56
to the side linkage 58 of the inner left phalange 38 and has a
series of external inner rod threads 150. The threads 150 define a
thread pattern that is substantially similar to the thread pattern
that is characteristic of a triple threaded screw. The threads 150
advantageously, but not necessarily, begin adjacent to the inner
radial surface 146 of the inner brake pulley 134 and terminate
adjacent to the side linkage 58 of the inner left phalange 38.
As depicted in FIGS. 4-5, the inner left brake 136 includes an
inner left brake disc 152. The disc 152 has a substantially
circular body 154 formed integral with an inner left brake arm 156.
It thus somewhat resembles a common frying pan.
The inner brake disc 152 is disposed around the portion of the
inner brake rod 138 which has the inner rod threads 150. It defines
a centrally located bore which has a series of internal brake
threads 158 that can mate with and thereby, engage the inner rod
threads 150. The brake threads 158, therefore, too define a thread
pattern that is substantially similar to the thread pattern
characteristic of a triple threaded screw. However, as evident from
FIG. 4, the length of the thread pattern formed by the brake
threads 158 is smaller than the length of the thread pattern formed
by the inner rod threads 150. Therefore, similarly to a nut located
on a threaded bolt, the inner brake disc 152 can be threaded along
the inner brake rod 138 and into engagement with the inner radial
surface 146 of the inner brake pulley 134. It thus provides a
braking force which can restrain rotation of the inner brake pulley
134.
The top portion 160 of the inner brake arm 156 defines an axial
opening for securely receiving an inner arm rod 162 that has an
inner arm roller 164 preferably securely disposed around it. When
the inner arm rod 162 is received in this manner, the common
transverse axis of the rod 162 and inner arm roller 164 is oriented
substantially parallel to the transverse axis of the inner left
brake rod 138. Moreover, the inner arm roller 164 has substantially
the same in width as the width of the inner brake pulley 134.
For the purpose of more selectively and effectively regulating the
braking force exerted by the left brake disc 152, the inner left
brake 136 also advantageously includes a pair of oppositely
disposed inner left biasing elements 166 and 168, which can be
suitable helical springs. The biasing element 166 has one of its
ends secured to the top portion 160 of the inner brake arm 156 and
its other end secured to the side linkage 58 of the inner left
phalange 38. The biasing element 168 has one of its ends secured to
the top portion 160 of the inner brake arm 156, while its other end
is secured to the side linkage 56 of the inner left phalange
38.
As shown in FIG. 5, the equilibrium or rest position of the inner
left brake 136 corresponds to the position in which the left thumb
16 is fully extended. In this equilibrium position, therefore, the
biasing element 166 exerts a threshold initial spring force on the
inner brake arm 156. This tensile or pulling force maintains the
inner brake disc 152 in its equilibrium state of engagement with
the inner rod threads 150. This in turn provides the inner brake
disc 152 with a threshold braking force that is initially exerted
on the inner radial surface 146 of the inner brake pulley 134. The
inner brake pulley 134, therefore, is restrained from rotating
clockwise relative to the inner brake rod 138.
As will become more evident from later discussion, the inner brake
disc 152 will not further engage the inner rod threads 150, and
thereby will not move further inward against the inner radial
surface 146 of the pulley 134, until any force incident on the
inner arm roller 164 is sufficient to move the inner brake arm 156
downward. This force will also have to overcome the threshold
restoring force of the biasing element 168. In the event that there
is sufficient force, the inner brake arm 156 will move downward and
the inner brake disc 152 will further engage the inner rod threads
150. Thus, the braking force against the inner brake pulley 134
will augment and, thereby, further resist rotation of the inner
brake pulley 134. The braking force will tend to be greatest
whenever the force incident on the inner arm roller 164 has caused
the biasing element 166 to become substantially fully compressed or
when the inner brake disc 152 simply cannot move further
inward.
It will be understood that a triple threaded screw pattern is
particularly advantageous here, since it facilitates speedy
movement of the inner brake disc 152 in either direction along the
inner brake rod 138. The inner brake pulley 134 and the inner brake
disc 152, therefore, tend not to remain undesirably locked together
after braking the force has subsided The inner left brake 136 thus
tends to more easily reassume its equilibrium position.
It will be appreciated that it is desirable that the inner left
brake 136 continually be able to reassume its return equilibrium
position shown in FIG. 5. Generally, the inner brake 136 will tend
to do so when any force incident on the inner arm roller 164
subsides such that there is decrease in the braking force exerted
by the inner brake disc 152. At this point, the restoring force of
the biasing element 166 in its compressed condition will tend to
help overcome the subsiding force incident on the inner arm roller
164 and urge the inner arm rod 162 upward. In some cases, however,
remnant frictional forces that may exist between the inner brake
pulley 134 and the inner brake disc 152 may counteract the
restoring force of the biasing element 166 and, therefore, tend to
prevent the inner left brake 136 from returning to equilibrium. In
that event, the biasing element 168 serves to provide an additional
force which counteracts the remnant frictional forces and assists
the inner left brake 136 in reassuming its equilibrium
position.
The inner left brake 136 is also associated with a somewhat
semi-ovular, but substantially flat, inner tendon brake pin 170. It
is situated within a radial bore within the inner brake pulley 134
and protrudes outwardly from the outer surface 172 of the inner
brake pulley 134. It is also secured to the pulley 134 by a
suitable screw pin 174 that fits within an axial bore in the pulley
134 and has a screw head which is substantially flush with the
outer radial surface 176 of the inner brake pulley 134.
The tendon brake pin 170 defines an inner tendon cavity 178 which
is situated adjacent the outer surface 172 of the inner brake
pulley 134. The pin 170 also has its transverse axis oriented
substantially perpendicular to the transverse axis of the screw pin
174. The functions of the screw pin 174 and tendon pin 170 will
become evident during later discussion of the pitching or pivoting
of the left thumb 16.
In order to prevent the inner left brake disc 152 from undesirably
locking with the inner brake pulley 134, the inner left brake 136
can also include a suitable inner left friction plate 180 which is
disposed around the inner brake rod 138. The plate 180 is
interposed between the inner brake disc 152 and the friction pad
144 associated with the inner brake pulley 134 such that it is
substantially contiguous with the friction pad 144 and the inner
brake disc 152. (See FIG. 4.) It also has a hollow inner friction
stem 182 which protrudes transversely toward the middle left joint
76 and is slidably connected to a slender secondary brake pin 184.
The secondary brake pin 184 is connected to the side linkage 58 of
the inner left phalange 38. Consequently, the inner friction plate
180 will tend to only translate, rather than also rotate, along the
inner brake rod 138. The absence of any significant rotation will
make the friction plate 180, and thus the inner brake disc 152,
less conducive to locking with the inner brake pulley 134. Thus,
when the application of braking force is not desired, the inner
brake pulley 134 can function more independently of the inner brake
136.
It will be appreciated that the particular types of biasing
elements 166 and 168 and other components of the inner shape
adaption mechanism 130 chosen will substantially depend upon the
dynamics of the left thumb 16 and the particular tasks to be
accomplished. As will become evident below, however, the biasing
elements 166 and 168 preferably have the requisite force
characteristics to permit the desired controlled, sequential
pitching or pivoting of the left phalanges 34, 36 and 38 relative
to each other and of the left phalanges 34, 36, and 38 relative to
the left thumb base or base linkage 40.
The outer shape adaption mechanism 132 is constructed essentially
similar to, and functions essentially alike, the inner shape
adaption mechanism 130. More particularly, as depicted in FIGS.
4-5, the outer shape adaption mechanism 132 is situated between the
outer and middle left thumb joints 74 and 76. It includes an outer
left brake pulley 186 and an outer left brake 186 which are each
disposed around an outer left brake rod 190.
The outer brake pulley 186 is selectively rotatable relative to the
outer brake rod 190 and has a centrally located inner bore 192
which receives needle or other suitable bearings 194. The bearings
194 are abutable with the outer brake rod 190. They, therefore,
tend to reduce frictional forces between the outer brake rod 190
and the outer brake pulley 186 and to facilitate proper rotation of
the pulley 186. The outer brake pulley 186 can also have a suitable
friction pad 196 affixed to its inner radial surface 198 for
reducing wear on the pulley 186.
The outer left brake rod 190 extends axially through the interior
of the left thumb 16 and is received through bores (not shown) in
opposing side linkages 52 and 54 of the middle left phalange 36. It
is also secured to the side linkage 52 of the middle left phalange
36 by an appropriate set screw 200. The outer brake rod 190 further
becomes tapered as it extends from the side linkage 52 of the
middle left phalange 36 and has a series of external outer rod
threads 202. The threads 202 form a thread pattern which is
substantially similar to the triple threaded screw thread pattern
discussed above. The threads 202 advantageously, but not
necessarily, begin adjacent to the inner radial surface 198 of the
outer brake pulley 186 and terminate adjacent to the side linkage
54 of the middle left phalange 36.
The outer left brake 188 includes an outer left brake disc 204
which has a substantially circular body 206 formed integral with an
outer left brake arm 208. Like the inner left brake 136, it,
therefore, substantially resembles a common frying pan. The outer
brake disc 204 is disposed around the portion of the outer brake
rod 190 which has the outer rod threads 202. It defines a centrally
located bore which has a series of internal brake threads 210 that
can mate with and, thereby, engage the outer rod threads 202. The
internal brake threads 210, therefore, form a thread pattern that
is substantially similar to the triple threaded screw pattern
discussed above. However, the length of thread pattern formed by
the brake threads 210 is again smaller than the length of thread
pattern formed by the outer rod threads 202. Therefore, the outer
brake disc 204 can be threaded along the outer brake rod 190 and
into engagement with the inner radial surface 198 of the outer
brake pulley 186. This provides a braking force which can restrain
the rotation of the outer brake pulley 186.
Like the inner brake arm 156, the top portion 212 of the outer
brake arm 208 defines an axial opening for securely receiving an
outer arm rod 214 that has an outer arm roller 216 preferably
rotatably disposed around it. In like manner to the inner left
brake 136, the outer left brake 188 also advantageously includes an
oppositely disposed pair of outer left biasing elements 218 and
220, which can be suitable helical springs. The biasing element 218
has one of its ends secured to the top portion 212 of the outer
brake arm 208 and its other end secured to the side linkage 54 of
the middle left phalange 36. The biasing element 220 has one of its
ends secured to the top portion 212 of the outer brake arm 208,
while its other end is secured to the side linkage 52 of the middle
left phalange 36.
As shown in FIG. 5, the outer left brake 188 occupies an
equilibrium or rest position similar to that occupied by the inner
left brake 136. Thus, in this equilibrium position, the biasing
element 220 exerts a threshold initial tensile or pulling force on
the outer brake arm 208. This tensile or pulling force maintains
the outer brake disc 204 in its equilibrium state of engagement
with the outer rod threads 202. This in turn provides the outer
brake disc 204 with a threshold braking force that is initially
exerted on the inner radial surface 198 the of outer brake pulley
186. The outer brake pulley 186 is, therefore, restrained from
rotating clockwise relative to the outer brake rod 190.
As will become evident from later discussion, the outer brake disc
204 will not further engage the outer rod threads 202, and thereby
will not move further inward against the inner radial surface 198
of the pulley 186, until any force incident on the outer arm roller
216 is sufficient to move the outer brake arm 208 downward. This
force will also have to overcome the threshold restoring force of
the biasing element 220. In the event that there is sufficient
force, the outer brake arm 208 will move downward and the outer
brake disc 204 will further engage the outer rod threads 202. Thus,
the braking force against the outer brake pulley 186 will augment
above its threshold level and, thereby, further resist rotation of
the outer brake pulley 186. The braking force will tend to be the
greatest whenever the force incident on the outer arm roller 216
has caused the biasing element 218 to become substantially fully
compressed or simply when the outer brake disc 204 cannot move
further inward.
As with the inner left brake 136, it is also desirable to ensure
that the outer left brake 188 return substantially fully to its
equilibrium position shown in FIG. 5. In like manner, therefore,
the biasing element 220 of the outer brake 188 serves to provide an
additional force for counteracting any remnant frictional forces
between the outer brake pulley 186 and the outer brake disc
204.
Like the inner left brake 136, the outer left brake 188 also has a
similar outer tendon brake pin 222 secured by a suitable screw pin
224. (See FIG. 4.) The tendon brake pin 222 defines an outer tendon
cavity 226 which is situate adjacent to the outer surface 228 of
the outer brake pulley 186. Moreover, the outer left brake 188 can
also include a suitable outer left friction plate 230 which is
disposed around the outer brake rod 190. The plate 230 is
substantially similar to the friction plate 180 associated with the
inner left brake 136 and is interposed between the outer brake disc
204 and the friction pad 196 associated with the outer brake pulley
186. The plate 230 also has a similar hollow friction stem 232
which protrudes toward the outer left joint 74 and is slidably
connected to a slender, tertiary brake pin 234. The tertiary brake
pin 234 is similar to the secondary brake pin 184 of the inner
brake 136 and is connected to the side linkage 54 of the middle
left phalange 36. It also functions similar to that of the
secondary brake pin 184.
As with the inner left brake 136, it will be appreciated that the
particular type of biasing elements 218 and 220 and other
components of the outer shape adaption mechanism 132 chosen will
depend upon the dynamics of the left thumb 16 and the particular
task to be accomplished. However, the biasing elements 218 and 220
again preferably have the requisite force characteristics to permit
the desired controlled pitching or pivoting referred to above.
Similar to the left thumb 16, the right thumb 18 includes outer,
middle and inner right thumb phalanges or linkages 238, 240 and 242
which together are coupled to a right thumb base or base linkage
244. (See FIGS. 2 and 12-13.) The right phalanges 238, 240 and 242
and the right base linkage 244 are interconnected similar to the
manner in which their counterpart left thumb phalanges 34, 36, 38
and left base linkage 40 are interconnected. Likewise, the right
thumb base 244 includes an oppositely disposed pair of somewhat
knuckle shaped right links 246 and 248 that are securely seated on
a right base plate 250 that has a substantially circular
cross-section. (See FIG. 3(a).)
As more fully discussed below, the right thumb base 244 is
connected to the right thumb engagement sub-assembly 24 so as to
permit the right thumb 18 to yaw, roll and pitch or pivot relative
to three separate right thumb axes running through the right thumb
base 244. With reference to FIG. 3(a), it will be observed that the
axis passing vertically through the right thumb base 244
corresponds to the axis relative to which the right thumb 18 yaws
(hereinafter, "right thumb base yaw axis".) The axis passing
horizontally through the right thumb base 244 which is associated
with rolling of the right thumb 18 (hereinafter, "right thumb base
roll axis".) The remaining axis, which is substantially orthogonal
to the transverse axis of the right thumb 18 in its fully extended
position shown in FIG. 2, is associated with pitching or pivoting
of the right thumb 18 (hereinafter, "right thumb pitch or pivoting
base axis".) It preferably moves along with the right thumb 18 when
it yaws. Similar to the left thumb base axes, the right thumb base
axes are advantageously, but not necessarily, mutually orthogonal
to each other. The configuration and construction of the right
thumb 18 is similar to that described above for the left thumb 16.
Thus, it will be understood that the right thumb 18 would also
appear as shown in FIGS. 4-5 and, thereby, have similar outer,
middle and inner base, right thumb joints, inner and outer right
shape adaption mechanisms and other similar components.
Similar to the thumbs 16 and 18, the finger 14 includes outer,
middle, and inner finger phalanges 262, 264 and 266 which together
are coupled to a finger base or base linkage 268. The finger
phalanges 262, 264 and 266 and finger base linkage 268 are
interconnected similar to the manner in which their counterpart
left phalanges 34, 36 and 38 and left linkage 40 are
interconnected. Likewise, the finger base linkage 268 includes a
pair of oppositely disposed somewhat knuckle shaped finger links
270 and 272 that are securely seated on a finger base plate 274
that has a substantially circular cross-section. The links 270 and
272 can also be joined together and formed integral with a face
plate 276. (See FIG. 3(b).)
As more fully discussed below, the finger base linkage 268 is
connected to the finger engagement subassembly 26 so as to permit
the finger 14 to yaw and pitch or pivot relative to two separate
finger base axes running through the finger base 268. With
reference to FIG. 3(b), it will be observed that the axis passing
vertically through the finger base 268 corresponds to the axis
relative to which the finger 14 yaws (hereinafter, "finger yaw base
axis".) The remaining axis, which is substantially orthogonal to
the transverse axis of the finger 14 in its fully extended position
(shown in FIG. 2), is associated with pitching or pivoting of the
finger 14 (hereinafter, "finger pitch or pivoting base axis".) It
preferably moves along with the finger 14. The finger base axes are
advantageously, but not necessarily, mutually orthogonal to each
other. The configuration and construction of the finger 14 is
similar to that described above for the left thumb 16. Thus, the
finger 14 would also appear as shown in FIGS. 4-5 and, thereby,
have similar outer, middle and inner or base right thumb joints,
inner and outer finger shape adaption mechanisms and other similar
components.
In accordance with another feature of the invention, the engagement
sub-assemblies 22 and 24 selectively cause the thumbs 16 and 18
respectively to engage in yawing, rolling and pitching or pivoting
motions and versatilely assume multiple configurations. Further,
the engagement sub-assembly 26, selectively causes the finger 14 to
engage in yawing and pitching or pivoting motions, and versatilely
assume multiple configurations. As set forth below, each
sub-assembly 22, 24 and 26 has an assemblage of shafts, gears,
motors and tendons that accomplish the engagement aforementioned
functions.
More specifically, and with reference first to engagement of the
left thumb 16, the left sub-assembly 22 includes a left thumb,
primary drive shaft 300 and a left thumb, secondary drive shaft 302
which is substantially concentric with and rotatably disposed
around the left primary shaft 300. (See FIG. 3(c).) The left
primary and left secondary shafts 300 and 302 are oriented such
that their common transverse axis is substantially parallel to the
transverse axis of the left thumb 16 in its fully extended or rest
position shown in FIG. 2. Their common transverse axis is also
substantially parallel to the left thumb base axis associated with
rolling motion of the left thumb 16. (See FIG. 3(c).)
For the purpose of inducing yawing motion of the left thumb 16, the
left sub-assembly 22 includes a left yaw motor 304 and a left yaw
gear sub-assembly 306. As depicted in FIG. 3(c) the left yaw motor
304 is rotatably connected near one end of the left primary shaft
300 and can rotate the shaft 300 in either a clockwise or
counterclockwise direction. It can also be mounted within or
surrounded by, a suitable left yaw motor housing 307. (See FIGS. 1
and 11.) The motor 304 can be any suitable dc or stepper motor or
any other motor that can provide the requisite actuation of the
left primary shaft 300.
The left yaw gear sub-assembly 306 has a left thumb yaw worm gear
308 which is engageable with a left thumb yaw worm 310. The left
yaw worm gear 308 is mounted on a left linkage shaft 312 for
rotation with the left linkage shaft 312. The top portion of the
left linkage shaft 312, protrudes through an aperture (not shown)
in the left thumb base 40 and is secured to the left thumb base 40.
(See FIGS. 3(c) and 11.) Consequently, the left thumb base 46 is
movable along with the left linkage shaft 312. When so secured, the
transverse axis of the shaft 312 is substantially parallel to the
left thumb base axis associated with yawing motion of the left
thumb 16. The left yaw worm 310 is mounted for rotation near the
remaining free end of the left primary shaft 300. It, therefore,
has its transverse axis oriented substantially parallel to the
common transverse axis of the left primary and secondary shafts 300
and 302.
Upon actuation by the left yaw motor 304, the left primary shaft
300 rotates and, thereby, causes the left yaw worm 310 to engage
the left yaw worm gear 308. This engagement substantially
simultaneously induces the left linkage shaft 300 and left thumb
base 40 to rotate together with the left yaw worm gear 308.
Consequently, the left thumb 16 yaws in a plane substantially
orthogonal to the transverse axis of the linkage shaft 312.
Relative to its fully extended or rest position shown in FIG. 2,
the left thumb 16 can also yaw in a plane that is substantially
parallel to the plane in which the left primary and left secondary
shafts 300 and 302 are located. That is, it yaws about the left
thumb base axis associated with yawing motion. (See FIG. 3(c).)
For the purpose of inducing rolling motion of the left thumb 16,
the left sub-assembly 22 further includes a left roll motor 314 and
a left roll gear sub-assembly 316. The left roll motor 314 has a
left roll shaft 318 which is rotatably connected to it and can
rotate the shaft 318 in either a clockwise or counterclockwise
direction. It can also be surrounded by a suitable left roll motor
housing 319. (See FIGS. 1 and 10.) The motor 314 can be any
suitable dc or stepper motor or any other motor that can provide
the requisite actuation of the left roll shaft 318 so as to drive
the left roll sub-assembly 316. The transverse axis of the left
roll shaft 318 is oriented substantially orthogonal to the common
transverse axis of the left primary and secondary shafts 300 and
302.
The left roll gear sub-assembly 316 includes a left roll housing
320, which is secured to one end of the left secondary shaft 302,
and a left roll worm gear 322, which is secured to the left
secondary shaft 302 toward the other end of the left secondary
shaft 302. The housing 320 surrounds the left yaw gear sub-assembly
306 and helps stabilize the left yaw gear sub-assembly 306 and
otherwise enhances the operational characteristics of the left
thumb 16. As depicted in FIGS. 3(c), 9 and 11, it further defines a
side aperture 324 for receiving the left primary shaft 300 and a
top aperture (not shown) for receiving the left linkage shaft 312.
As such, the left thumb base 40 is substantially contiguous with
the top surface of the left roll housing 320. (See FIG. 3(c).)
Suitable bearings 326 can also be situated between the housing 320
and left primary shaft 300 in order to stabilize the shaft 300.
(See FIG. 10.) In that case, suitable sleeves 328 and 330 can be
disposed around the shaft 300 in order to strengthen it and better
retain the bearings 326. Suitable upper and lower bearings 332 and
334 can further be situated between the housing 320 and the left
linkage shaft 312 in order to better stabilize the shaft 312 during
operation. (See FIG. 11.) To a similar end, thrust or other
suitable bearings 336 can be located between the housing 320 and
left thumb base 40. A suitable nut 338 can also be attached to the
bottom of the left linkage shaft 312 in order to maintain the lower
bearings 334 in the housing 320. Moreover, the left linkage shaft
312 can be associated with a suitable key 340 for facilitating
torque transmission between the left yaw worm gear 308 and the left
linkage shaft 312.
The left roll worm gear 322 defines a centrally disposed left roll
bore 342 for permitting the left primary shaft 300 to pass through
it to the left yaw motor 304. The left roll worm gear 344 is also
engageable with a left roll worm 344 that is mounted for rotation
with the left roll shaft 318. As shown in FIG. 9 the left roll
housing 320 can also be associated with an elongated yaw limit
plate 346 that is connected to the left thumb base 40. It serves to
limit the degree of yawing of the thumb 16 upon contact with a
limit pin 348 that protrudes from the top of the housing 320.
Upon actuation by the left roll motor 314, the left roll worm 344
engages the left roll worm gear 322 such that the left secondary
shaft 302 rotates with the left roll housing 320 about the common
transverse axis of the left primary and secondary shafts 300 and
302. At the same time, the housing 320 carries along the left thumb
base 40. Consequently, the left thumb 16 rolls in a plane
substantially orthogonal to the common transverse axis of the left
primary and secondary shafts 300 and 302. That is, it rolls
relative to the left thumb base axis associated with rolling
motion. (See FIG. 3(c).)
It will be observed that the left thumb 16 is capable of rolling at
least substantially 180 in either a clockwise or counterclockwise
direction in light of the reversibility of the left roll motor 314.
Thus, in the event that the left thumb 16 were initially in the
extended or rest position shown in FIG. 2, it would rotate
substantially ninety degrees to assume the roll position shown in
FIG. 1. As viewed from the frame of reference of an observer
sitting on the sphere 12 and viewing the thumb 16, the rotation
would be clockwise. Conversely, the thumb 16 would rotate
counterclockwise to reassume its previous position. It will further
be observed that the left primary and secondary shafts 300 and 302,
left yaw gear sub-assembly 306 and left roll gear sub-assembly 316
together effectively cooperate as one preferred form of a left
thumb yaw and roll gear sub-assembly that causes yawing and rolling
of the left thumb 16.
In like manner to the left yaw gear sub-assembly 306, the left roll
gear sub-assembly 316 can be surrounded by a suitable housing 350
that is itself secured to the left roll motor housing 319. (See
FIGS. 1, 9-10.) In that event, suitable bearings 352 can be
situated between the housing 350 and the left secondary shaft 302.
(See FIG. 10.) Further, the left secondary shaft 302 can be
associated with a suitable key 354 for facilitating torque
transmission with the left roll worm gear 322. Suitable bearings
356 can further be situated between the left roll shaft 318 and the
housing 350. In that event, sleeves 358 and 360 can also be
disposed about the shaft 318 on opposing sides of the left roll
worm 344 in order to strengthen the shaft and better retain the
bearings 356. (See FIG. 9.) It will be understood that the
aforementioned additional features tend to enhance the overall
stability and operational characteristics of the left thumb 16.
For the purpose of inducing pivoting or pitching motion of the left
thumb 16, the left engagement subassembly 22 further includes a
left pitch motor 362 which actuates a left thumb tendon or cable
364 through driving a left thumb pitch gear sub-assembly 366. (See
FIG. 3(c).) The left pitch motor 362 has a left pitch shaft 368
which is rotatably connected to it and can rotate the pitch shaft
368 in either a clockwise or counterclockwise direction. It can
also be surrounded by a suitable left pitch motor housing 370. (See
FIGS. 1 and 9.) The motor 362 can be any suitable dc or stepper
motor or any other motor that can provide the requisite actuation
of the left pitch shaft 368 so as to drive the left pitch
sub-assembly 366. The transverse axis of the left pitch shaft 368
is oriented substantially orthogonal to the common transverse axis
of the left primary and secondary shafts 300 and 302. The left
pitch shaft 368 further lies in a plane substantially parallel to
the plane in which the shafts 300 and 302 are located.
The left pitch gear sub-assembly 366 has a left pitch worm gear 372
which is substantially contiguous with a left reducer drum 374.
(See FIGS. 3(c), 9, and 14.) Both the left pitch worm gear 372 and
left reducer drum 374 are mounted for rotation with a left reducer
shaft 376. The left worm gear 372 is engageable with a left pitch
worm 378 that is mounted for rotation on the left pitch shaft 368.
(See FIGS. 3(c) and 9.) As such, the left reducer shaft 376 has its
transverse axis oriented substantially orthogonal to the transverse
axis of the left pitch shaft 368.
The left pitch gear sub-assembly 366 can also be provided with
additional features which enhance the stability and operational
characteristics of the left thumb 16 and left pitch sub-assembly
366. More specifically, the left pitch sub-assembly 366 can be
surrounded by a suitable left reducer housing 380 which is itself
secured to the left pitch motor housing 370. (See e.g. FIGS. and
9.) Suitable bearings 382 can also be situated between the housing
380 and the left pitch shaft 368. Suitable sleeves 384 and 386 can
further be disposed around the left pitch shaft 368 on opposing
sides of the left pitch worm 378 to strengthen the shaft 368 and
retain the bearings 382. (See FIG. 9.)
Likewise, suitable upper and lower bearings 388 and 390 can be
situated between the left reducer shaft 376 and the housing 380 to
stabilize the shaft 376. (See FIG. 14.) The upper and lower
bearings 388 and 390 can also be retained within the housing 380 by
appropriate washers or nuts 391 and 392 connected near opposing end
portions of the left reducer shaft 376. (See FIG. 14.) Moreover,
the left reducer shaft 376 can also have suitable keys 393 for
facilitating torque transmission between the shaft 376 and the left
drum 374 and left pitch worm gear 372. The left drum 374 and left
pitch worm gear 372 can also be better mounted for rotation with
each other by a suitable screw 394 threaded through co-axial bores
(not shown) in the left drum 374 and left pitch worm gear 372. When
so threaded, the transverse axis of the screw 394 is substantially
parallel to the left reducer shaft 376. (See FIG. 14.)
The left thumb tendon 364 is wrapped around the left reducer drum
374 and connected to the left thumb 16 in a manner that permits
pitching or pivoting not only of the left thumb 16 at its inner or
base left joint 78 but also of the left thumb phalanges 34, 36 and
38 relative to each other. More specifically, as shown in FIG. 3(c)
the left thumb tendon 364 wraps around the left reducer drum 374
for a plurality of revolutions in such a way that it forms upper
and lower left leads 395 and 396 that extend from the drum 374 to
the left thumb 16 through bores (not shown) in the left reducer
housing 380. (See e.g. FIGS. 1 and 3(c).)
Moreover, the left drum 374 can further be partially surrounded by
an arcuate plate 397 which assists in retaining the left thumb
tendon 364 on the left drum 374. (See FIGS. 9, 14.) The plate 397
and outer surface of the drum 372 define an arcuate channel and the
plate 397 is secured to the drum by pins 398 and a screw 399.
Both leads 395 and 396 pass along the exterior of the hand and
enter the interior of the left thumb 16 through bores (not shown)
in the left thumb base linkage 40. (See e.g. FIGS. 1, 3(c) and 9.)
The portion of the left thumb tendon 364 that extends between the
exterior of the left thumb 16 and the left reducer housing 380 can
also be surrounded by an appropriate tubular casings 399a for
preserving the useful life of the left tendon 328 (casings only
partially shown in FIGS. 4 and 9-10.)
The upper lead 395 first contacts or is received by the underside
of the left link pulley 72 which serves to guide the upper lead 395
into proper contact with the inner left pulley 108. The upper lead
395 then wraps successively around the inner, middle and outer left
pulleys 108, 92 and 80 in a counterclockwise wrapping direction
before terminating at the left tendon pin 66 to which it is firmly
secured. It will be observed that the wrapping is initiated around
the top of the outer surface of each of the pulleys 108, 92 and 80.
(See FIG. 5.)
As depicted in FIG. 5, the lower lead 396 first contacts the
underside of the outer surface of inner left pulley 110 and wraps
around the pulley 110 in a clockwise wrapping direction. It then
contacts the upper surface of the inner arm roller 164 associated
with the inner brake arm 156 and wraps around the inner brake
pulley 134 in a counterclockwise wrapping direction. Thereafter,
the lower lead 396 contacts the underside of middle left pulley 94
and wraps around the middle left pulley 94 in a clockwise wrapping
direction. It will be observed that the wrapping process around the
inner brake pulley 134 begins with the lower lead 396 contacting
the top of the outer surface of 172 the pulley 134. On the other
hand, the wrapping process around the underside of the outer
surface of the middle left pulley 94 begins with the lower lead 396
contacting the underside of the pulley 94.
Afterwards, the lower lead 396 contacts the upper surface of the
outer arm roller 216 associated with the outer brake arm 208 and
winds around the outer surface 228 of outer brake pulley 186 in a
counterclockwise wrapping direction. Again, it will be observed
that the wrapping process begins with the lower lead 396 being
received by the top of the outer surface 228 of the outer brake
pulley 186. Finally, the lower lead 396 wraps around the underside
of the outer surface of the outer left pulley 80 before terminating
at the left tendon pin 66 to which it is firmly secured.
It will be appreciated that the lower lead 396 can be affixed to
the inner brake pulley 134 and outer brake pulley 186 by inserting
it through the inner and outer left tendon cavities 178 and 226 in
the inner and outer tendon brake pins 170 and 222 respectively.
This will tend to minimize undesirable slippage of the lower lead
396. The left thumb tendon is preferably a suitable sheathed cable.
It will be, however, be appreciated that the left thumb tendon 364
can be any suitable tendon, cable or cord which has the requisite
strength and tautness for proper pivoting and retraction of the
left thumb 16 and its respective left thumb phalanges 34, 36 and
38. Each of the leads 395 and 396 can also be wrapped around the
various pulleys in other ways that achieve the desired pitching and
retraction of the left thumb 16 in accordance with the
invention.
Upon actuation by the left pitch motor 362, the left pitch worm 378
engages the left pitch worm gear 372, thereby causing the left
reducer drum 374 to rotate about the transverse axis of the left
reducer shaft 376. Since the left pitch motor 362 can rotate the
left pitch shaft 368 in either a clockwise or counterclockwise
direction, the left reducer drum 374 can similarly rotate either
clockwise or counterclockwise. As evident from FIG. 3(c), clockwise
rotation of the left reducer drum 374 would apply tension to the
upper lead 395. This would cause the upper lead 395 to tend to wrap
further around the left drum 374 and the lower lead 396 to tend to
uncoil from it. Consequently, and as discussed more fully later,
the left thumb 16 would be retracted. Relative to the configuration
of the left thumb 16 shown in FIG. 1, the retraction would commence
at the outer left phalange 34. Conversely, when the left drum 374
rotates in a counterclockwise direction, it would apply tension to
the lower lead 396. Therefore, the lower lead 396 would tend to
wrap further around the left drum 374 while the upper lead 395
would tend to uncoil from it. Consequently, and as discussed below,
the left thumb 16 and its corresponding phalanges 34, 36 and 38
would pitch or pivot.
The particular manner in which the inner and outer shape adaption
mechanisms 130 and 132 control the sequence of pitching or pivoting
of the left phalanges 34, 36 and 38 will now be discussed with
reference to certain exemplary pivoting or pitching situations.
More specifically, consider the following first situation: The left
thumb 16 is in a fully extended configuration, such as that shown
in FIG. 2. Further, it is desired that the left thumb 16 pivot or
pitch relative to inner base joint so as to place itself in a
position more suitable for grasping and manipulating a certain
object. Moreover, at the time the desired pivoting or pitching is
to be initiated, the left thumb 16 is not yet in contact with the
object.
In that event, the left pitch motor 362 will actuate the left
reducer shaft 376 to rotate the left reducer drum 374 in a
counterclockwise direction. The lower lead 396, therefore, will
begin to be tensioned and the upper lead 395 slackened. This
tensile force would propagate along the lower lead 396 to the inner
pulley 110 of the inner base joint 78. At the same time, the other
inner pulley 108 will experience a reduction in tensile force from
the upper lead 395. Consequently, the inner, middle and left
phalanges 34, 36 and 38 as a whole would together pitch or pivot
downward relative to the left thumb base 40 and the inner pulleys
108 and 110 will tend to rotate somewhat in a counterclockwise
direction.
It will be observed that the aforementioned tensile force will also
propagate along the lower lead 396 to the inner shape adaption
mechanism 130. Thus, the inner brake pulley 134 will experience a
tensile force urging it to rotate clockwise. Moreover, the tensile
force will give rise to a downward force. This downward force will
become incident on the inner arm roller 164 and, consequently, on
the inner brake arm 156 of the inner brake disc 152. The tensile
force exerted on the inner brake pulley 134 will however, be
counteracted by the threshold braking force exerted on the inner
radial surface 146 of the inner brake pulley 134.
The threshold braking force will generally be sufficient to
overcome the aforementioned tensile force such that the inner brake
pulley 134 will not rotate. The absence of clockwise rotation of
the inner brake pulley 134 will thereby prevent the propagation of
sufficient tensile force to accomplish pivoting of the outer,
middle, inner and left phalanges 34, 36 and 38 relative to each
other. It will further be understood that, if the aforementioned
tensile force were somehow sufficient to cause the inner brake arm
156 to pivot downward, the inner brake disc 152 will apply
increasing braking force against the inner radial surface 146 of
the inner brake pulley 134. The resulting augmented braking force
would advantageously sufficiently counteract the tensile force so
as to still prevent rotation of the inner brake pulley 134.
Consider now, that it is desired to retract the thumb 16 so that it
can reassume its initial configuration. In that event, the left
pitch motor 362 will be reversed and, thereby, cause the left
reducer drum 374 to rotate in a clockwise direction. Tensile force
will then propagate along the upper lead 395, while the lower lead
396 will slacken. The inner left pulleys 108 and 110 will,
therefore, rotate in a clockwise direction. The outer, left and
middle phalanges 34, 36 and 38 as a whole would then pitch or pivot
upward and the inner pulleys 108 and 110 would tend to rotate in a
clockwise direction. The left thumb 16 would thereby reassume its
initial configuration. It will be observed that the above described
controlled sequential pivoting advantageously prevents the
phalanges 34, 36 and 38 from undesirably pivoting or pitching
arbitrarily relative to each other.
Consider the following second situation: As the left phalanges 34,
36 and 38 as a whole begin to pitch or pivot downward relative to
the inner base linkage 40, the area of the left thumb 16 between
the middle and base joints 76 and 78 is obstructed by an object. In
that event, the left pitch motor 362 will cause the left reducer
drum 374 to exert increasing tensile force on the lower lead 396 to
attempt to counteract the force exerted by the object in the
aforementioned area. This tensile force will again propagate to
both the inner left pulley 134 and the inner shape adaption
mechanism 130 as described above. As the tensile force increases,
it will become sufficient enough to move the inner brake arm 156
increasingly downward. The inner brake disc 152 will, therefore,
exert increasing braking force against the inner radial surface 146
of the inner brake pulley 134.
This resulting augmented braking force will increasingly counteract
the increasing tensile force until the biasing element 166 is
substantially fully compressed or simply until the inner brake disc
152 cannot move further inward along the inner brake rod 138.
Eventually, the tensile force will overcome the augmented braking
force. The inner brake pulley 134 will then rotate clockwise. Thus,
eventually sufficient tensile force will propagate to the middle
left pulley 94 so as to cause the middle left phalange 36 to pivot
or pitch downward relative to the inner left phalange 38. Further,
the middle left pulleys 92 and 94 will tend to rotate
counterclockwise. The middle left phalange 36 will then continue to
pivot around the object until the object obstructs further movement
of the phalange 36 by exerting force in the area between the outer
and middle left joints 74 and 76. It will be understood that during
this process the middle left pulley 92 will rotate counterclockwise
in light of the slackened condition of the upper lead 395.
Since further movement of the middle left phalange 36 is now
obstructed, the left pitch motor 362 will provide increasing
tensile force to the lower lead 396 so as to counteract the force
exerted by the object in the immediately aforementioned area. This
increasing tensile force will propagate to the outer shape adaption
mechanism 132 which will then function similarly to the inner shape
adaption mechanism 130. That is, the outer brake pulley 186 will
not begin to rotate clockwise until the tensile force has exceeded
the resulting augmented braking force applied by the outer brake
disc 204 against the inner radial surface 198 of the outer brake
pulley 186.
At that point, the outer brake pulley 186 will rotate clockwise.
Consequently, sufficient tensile force will propagate to the outer
left pulley 80 for the outer left phalange 34 to pitch or pivot
downward relative to the middle left phalange 36 until the outer
left phalange 34 contacts the object. Correspondingly, the outer
left pulley 80 will tend to rotate counterclockwise. It will be
appreciated that above described controlled sequential pitching or
pivoting of the phalanges will result in the left thumb 16
versatilely configuring itself so as to properly grip and
thereafter manipulate the object.
Suppose now that it is desired to retract the left thumb 16 such
that it assumes its initial fully extended configuration. Again,
the left pitch motor 362 will be reversed. The lower lead 396 will
then slacken, while tensile force will be exerted on the upper lead
395. As a result, the outer left phalange 34 would pitch or pivot
upward relative to the middle left phalange 36. The upward movement
will continue until the outer left phalange 34 assumes its initial
configuration relative to the middle left phalange 36. Thereafter,
the outer and middle left phalanges 34 and 36 as a whole will pitch
or pivot upward relative to the inner left phalange 38. This upward
movement will continue until the outer and middle left phalanges 34
and 36 assume their initial configuration relative to the inner
left phalange 38. Finally, the outer, middle and inner left
phalanges 34, 36 and 38 as a whole will pivot or pitch upward
relative to the left thumb base 40 until the left thumb 16 assumed
its initial configuration. It will be observed that during the
retraction process the various pulleys would also rotate in
directions opposite to their respective directions of rotation
during the above described pivoting or pitching process.
Consider now the following third situation: The left thumb 16 has
assumed the pitching or pivoting configuration described in the
first situation and an object then contacts the area of the thumb
located between the outer and middle left joints 74 and 76. In that
event, the left pitch motor 362 will cause the left reducer drum
374 to rotate counterclockwise. Thus, it will exert increasing
tensile force on the lower lead 396 to attempt to counteract the
force exerted by the object in the aforementioned area. This
tensile force will propagate to the outer shape adaption mechanism
132. Eventually, the increasing tensile force will overcome the
augmented brake force. Thus, as described above for the second
situation, the outer left phalange 34 will pivot or pitch downward
relative to the middle left phalange 36. However, the middle left
phalange 36 will not pivot or pitch relative to the inner left
phalange 38. It will be understood that retraction of the outer
phalange 34 relative to the middle phalange 38 will occur in the
manner described for situation two above.
Turning now to the engagement of the right thumb 18, the right
thumb sub-assembly 24 is constructed essentially similar to that of
the left thumb engagement sub-assembly and has similar operational
characteristics. (See FIGS. 1, 3(a), 9, 12 and 14.) It includes a
right thumb primary drive shaft 400 and a right thumb secondary
drive shaft 402 which is concentric with and rotatably disposed
around the right primary shaft 400 (see FIG. 3(a).) The right
primary and right secondary shafts 400 and 402 are oriented such
that their common transverse axis is substantially parallel to the
transverse axis of the right thumb 18 in its fully extended rest
position shown in FIG. 2. Their common transverse axis is also
substantially parallel to the right thumb base axis associated with
rolling motion of the right thumb 18. (See FIG. 3(a).) Further, the
right primary and right secondary shafts are situated in
essentially the same plane as the left primary and left secondary
shafts 300 and 302.
For the purpose of inducing yawing motion of the right thumb 18,
the right thumb engagement sub-assembly 24 includes a right yaw
motor 404 and a right yaw gear subassembly 406. As depicted in FIG.
3(a), the right yaw motor 404 is rotatably connected to the right
primary shaft 400 near one end of the shaft 400 and can rotate the
shaft 400 in either a clockwise or counterclockwise direction. The
motor 404 can also be surrounded by, or mounted within, a suitable
right yaw motor housing 408. (See FIGS. 2 and 14.) It can also be
any suitable dc motor or any other motor that can furnish the
requisite actuation of the right primary shaft 400.
The right yaw gear sub-assembly 406, has a right thumb yaw worm
gear 410 which is engageable with a right thumb yaw worm 412. The
right yaw worm gear 410 is mounted on a right linkage shaft 414 for
rotation with the right linkage shaft 414. The top portion of the
right linkage shaft 414 protrudes through an aperture (not shown)
in the right thumb base 244 and is secured to the right thumb base
244. (See FIGS. 3(a) and 14.) When so secured, the transverse axis
of the right linkage shaft 414 is substantially parallel to the
right thumb base axis associated with yawing motion of the right
thumb 18. Consequently, the right thumb base 244 is movable with
the right linkage shaft 414 about the yaw axis of the right thumb
base 244. It, therefore, has its transverse axis oriented
substantially parallel to the common transverse axis of the right
primary and secondary shafts 400 and 402.
Upon actuation by the right yaw motor 404, the right primary shaft
400 rotates and, thereby, causes the right yaw worm 412 to engage
the right yaw worm gear 410. This engagement substantially
simultaneously causes the right linkage shaft 414 and right thumb
base 244 to rotate along with the right yaw Worm gear 410.
Consequently, the right thumb 18 yaws in a plane substantially
orthogonal to the transverse axis of the right linkage shaft 414.
Relative to its rest position shown in FIG. 2, the right thumb 18
can also yaw in a plane substantially parallel to the common plane
in which the shafts 400 and 402 are located. That is, it yaws about
the right thumb base axis associated with yawing motion. (See FIG.
3(a).)
For the purpose of inducing rolling motion of the right thumb 18,
the right thumb engagement sub-assembly 24 further includes a right
roll motor 416 and a right roll gear sub-assembly 418. The right
roll motor 416 has a right roll shaft 420 which is rotatably
coupled to it and can rotate the shaft 420 in either a clockwise or
counterclockwise direction. It can also be surrounded by, or
mounted within, a suitable right roll motor housing 422. (See e.g.
FIGS. 1-2.) The motor can be any suitable dc or stepper motor or
any other motor that can provide the requisite actuation to the
right roll shaft 420 so as to drive the right roll sub-assembly.
The transverse axis of the right roll shaft 420 is oriented
substantially orthogonal to the common transverse axis of the right
primary and secondary shafts 400 and 402. The right roll shaft 420
also lies in a plane that is substantially parallel to the common
plane in which the shafts 400 and 402 are located.
As shown in FIGS. 1, 9, 12 and 14 the right roll gear sub-assembly
24 includes a right roll housing 424, which is secured to one end
of the right secondary shaft 402, and a right roll worm gear 426,
which is secured to the right secondary shaft 402 toward the other
end of the shaft 402.
The right roll housing 424 surrounds the right yaw gear
sub-assembly 406 and helps stabilize the right yaw gear
sub-assembly 406 and otherwise enhances the operational
characteristics of the right thumb 18. As depicted in FIG. 3(a), it
further defines a side aperture 428 for receiving the right primary
shaft 400 and a top aperture (not shown) for receiving the right
linkage shaft 414. As such, the right thumb base 244 is
substantially contiguous with the top surface of the right roll
housing 424. Unlike the left roll housing 320, however, the side
aperture 428 of the right roll housing 424 is located along the
rear of the side 429 of the right roll housing 424.
Suitable bearings 430 can also be situated between the housing 424
and the right primary shaft 400 in order to stabilize the shaft
400. In that event, suitable sleeves 432 and 434 can be disposed
around the shaft 400 and on opposing sides of the right yaw worm
412 in order to strengthen it and better retain the bearings 430.
(See FIG. 9.) Suitable upper and lower bearings 436 and 438 can
further be situated between the housing 424 and right linkage shaft
414 to better stabilize the shaft 414 during operation of the right
thumb 18. (See FIG. 14.) A suitable nut 439 can also be affixed to
the bottom of the shaft 414 in order to maintain the lower bearings
438 in the housing 424. Moreover, the right linkage shaft 414 can
be associated with a suitable key 440 for facilitating torque
transmission between the right yaw worm gear 410 and the right
linkage shaft 414.
The right roll worm gear 426 defines a centrally disposed right
roll bore 442 for receiving the right primary shaft 400 such that
the shaft 400 passes through it to the right yaw motor 404. (See
e.g. FIG. 3(a).) The right roll worm gear 426 is also engageable
with a right roll worm 444 which is mounted for rotation on the
right roll shaft 420. Similar to the left roll housing 320, the
right roll housing 422 can be associated with a yaw limit plate and
yaw limit pin that cooperate to limit the degree of yawing of the
right thumb 18.
Upon actuation by the right roll motor 416, the right roll worm 444
engages the right roll worm gear 426 such that the right secondary
shaft 402 rotates with the right roll housing 424 about the common
transverse axis of the right primary and secondary shafts 400 and
402. Consequently, relative to its rest position shown in FIG. 2,
the right thumb 18 rolls in a plane substantially orthogonal to the
common transverse axis of the right primary and secondary shafts
400 and 402. That is, it rolls relative to the right thumb axis
associated with rolling motion.
It will be observed that the right thumb 18 is capable of rolling
at least substantially 180 in either a clockwise or
counterclockwise direction in light of the reversibility of the
right roll motor 416. Thus, in the event that the right thumb 18
was initially in its rest or extended position shown in FIG. 2, it
would rotate substantially ninety degrees to assume the position
shown in FIG. 1. As viewed from the frame of reference of an
observer sitting on the sphere 12 and viewing the thumb 18, the
rotation would be counterclockwise. Conversely, the thumb 18 would
rotate clockwise to reassure its previous position. It will further
be observed that the right primary and secondary shafts 400 and
402, right yaw gear sub-assembly 405 and right roll gear
sub-assembly 418 together effectively cooperate as one preferred
form of right thumb yaw and roll gear sub-assembly that causes
yawing and rolling of the right thumb 18.
In like manner to the right yaw gear sub-assembly 406, the right
roll gear sub-assembly 418 can be surrounded by a suitable housing
446 that is itself secured to the right roll motor housing 422 and
to the support structure 28 generally. (See FIG. 1, 9 and 12.) In
that event, suitable bearings 448 can be situated between the
housing 446 and the right secondary shaft 402. (See FIG. 9.)
Further, the right secondary shaft 402 can be associated with a
suitable key 450 for facilitating torque transmission with the
right roll worm gear 426.
Suitable bearings 452 can further be situated between the right
roll shaft 420 and the housing 446 in a manner similar to that for
the left roll shaft 318. (See FIG. 12.) In that event, sleeves 454
and 456 can also be disposed about the shaft 420 on opposing sides
of the right roll worm 444 in order to strengthen the shaft 420 and
better retain the bearings 452. It will be understood that the
aforementioned additional features tend to enhance the overall
stability and operational characteristics of the right thumb
18.
For the purpose of inducing pivoting or pitching motion of the
right thumb 18, the right engagement sub-assembly 24 further
includes a right pitch motor 458 which actuates a right thumb
tendon or cable 460 through driving a right thumb pitch gear
sub-assembly 462. As evident from comparing FIGS. 3(a) and (c), the
right engagement sub-assembly 24 is constructed essentially similar
to the left engagement sub-assembly 22. (See also FIGS. 9-12 and
14.) The right pitch motor 458 has a right pitch shaft 464 which is
rotatably connected to it and can rotate the right pitch shaft 464
in either a clockwise or counterclockwise direction. It can also be
surrounded by a suitable right pitch housing 466. (See e.g. FIG.
2.) The motor 458 can be any suitable dc or stepper motor or any
other motor that can provide the requisite actuation of the right
pitch shaft 464 so as to drive the right pitch sub-assembly 462.
The transverse axis of the right pitch shaft 464 is oriented
substantially orthogonal to the common transverse axis of the right
primary and secondary shafts 400 and 402. The right pitch shaft 464
also lies in a plane which is substantially parallel to the common
plane in which the shafts 400 and 402 are located.
The right pitch gear sub-assembly 462 is constructed essentially
similar to the left pitch gear sub-assembly 366. (See FIGS. 3(a)
and (c).) It has a right pitch worm gear 468 which is substantially
contiguous with a right reducer drum 470. Both the right pitch worm
gear 468 and right reducer drum 470 are mounted for rotation with a
right reducer shaft 472. The right worm gear 468 is engageable with
a right pitch worm 474 that is mounted for rotation on the right
pitch shaft 464. As such, the right reducer shaft 472 has its
transverse axis oriented substantially orthogonal to the transverse
axis of the right pitch shaft 464.
The right pitch gear sub-assembly 462 can also be provided with
additional features which enhance the stability and operational
characteristics of the right thumb 18 and right pitch sub-assembly
462 particularly. More specifically, the right pitch sub-assembly
462 can be surrounded by a suitable right reducer housing 476 which
is itself secured to the right pitch motor housing 466 and the
support structure 28 generally. (See dotted lines in FIG. 2 and see
FIG. 11.) In like manner to the left pitch shaft 368, suitable
bearings can also be situated between the housing 476 and the right
pitch shaft 464. Further, suitable sleeves can be disposed around
the right pitch shaft 464 on opposing sides of the right pitch worm
474 to strengthen the shaft 464 and retain the bearings.
Likewise, suitable upper and lower bearings 480 and 482 can be
situated between the right reducer shaft 472 and the housing 476 to
stabilize the shaft 472. (See FIG. 11.) The upper and lower
bearings 480 and 482 can also be retained within the housing 476 by
appropriate washers or nuts 484 and 486 connected to opposing end
portions of the shaft 472. Moreover, the right reducer shaft 472
can also have suitable keys 488 for facilitating torque
transmission between the shaft 472 and the right reducer drum 470
and right pitch worm gear 468. The right drum 470 and right pitch
worm gear 468 can also be better mounted for rotation with each
other by a suitable screw 490 threaded through co-axial bores (not
shown) in the right drum 470 and right pitch worm gear 468. When so
threaded, the transverse axis of the screw 490 is substantially
parallel to the right reducer shaft 472. (See FIG. 11.)
The right thumb tendon 460 is wrapped around the right reducer drum
470 and is connected to the right thumb 18 in a manner that permits
pitching or pivoting not only of the right thumb 18 at its inner or
base right joint but also of the right thumb phalanges 34, 36 and
38 relative to each other. It will be observed that the manner of
wrapping and connecting the right thumb tendon 460 is similar to
that employed for the left thumb tendon 364. (Compare FIGS. 3(a)
and (c) and see FIGS. 4-5.) More specifically, as shown in FIG.
3(a) the right thumb tendon 460 wraps around the right reducer drum
470 for a plurality of revolutions in such a way that it forms
upper and lower right leads 491 and 492 that extend from the right
reducer drum 470 to the right thumb 18 through bores (not shown) in
the right reducer housing 476. (See FIGS. 1-3 including dotted
lines in FIG. 2.)
Moreover, in a manner similar to that for the left tendon 364, the
right drum 470 can further be partially surrounded by an arcuate
plate which assists in retaining the right thumb tendon 460 on the
right reducer drum 470. (See FIG. 11.) As with the left reducer
drum 374, the plate and outer surface of the right reducer drum 470
define an arcuate channel and the plate is secured to the drum by
pins and a screw.
Both leads 491 and 492 pass along the exterior of the hand 10 and
enter the interior of the right thumb 18 through bores (not shown)
in the right thumb base 244. (See e.g. FIGS. 1 and 9.) The portion
of the right tendon 460 that extends between the exterior of the
right thumb 16 and the right reducer housing 476 can also be
surrounded by an appropriate tubular casings 494 for preserving the
useful life of the right tendon 460 (casings only partially shown
in FIG. 14.)
Since the left and right thumbs 16 and 18 are of similar
construction and operate similarly, it will be understood that the
upper and lower leads 491 and 492 of the right thumb 18 wrap around
the various right thumb pulleys and shape adaption mechanisms in
the same manner as the leads 395 and 396 of left thumb 16. Thus,
the upper and lower leads 491 and 492 would wrap essentially as
shown in FIG. 5. The lower lead 492 is also affixed to the
particular brake pulleys in the same manner as for the lower lead
396 of the left thumb 16. Additionally, as with the left thumb
tendon 364, the right thumb tendon 460 is preferably made of a
suitable sheathed cable. It can, however, be any tendon, wire or
cord which has the requisite strength and tautness for proper
pitching and retraction of the right thumb 18 and its phalanges
238, 240, and 242. Moreover, like the leads 395 and 396 of the left
thumb 16, the leads 491 and 492 can also be wrapped in various
other ways.
It will be appreciated that pitching or pivoting of the right thumb
18 occurs in a manner similar to that for the left thumb 16. That
is, upon actuation by the right pitch motor 458, the right pitch
worm 474 engages the right pitch worm gear 468, thereby causing the
right reducer drum 470 to rotate about the transverse axis of the
right reducer shaft 472. Since the right pitch motor 458 can rotate
the right pitch shaft 464 in either a clockwise or counterclockwise
direction, the right reducer drum 470 can similarly rotate either
clockwise or counterclockwise. As evident from FIG. 3(a), clockwise
rotation of the right reducer drum 470 would apply tension to the
upper lead 491. This would cause the upper lead 491 to tend to wrap
further around the right drum 470 and the lower lead 492 to tend to
uncoil from it.
Consequently, the right thumb 18 would be retracted. Relative to
the configuration of the right thumb 18 shown in FIG. 1, the
retraction would commence at the outer right phalange 238.
Conversely, when the right drum 470 rotates in a counterclockwise
direction, it would apply tension to the lower lead 492. Therefore,
the lower lead 492 would ten to wrap further around the drum 470
while the upper lead 491 would tend to uncoil from it.
Consequently, right thumb 18 and its corresponding phalanges 238,
240 and 242 would pitch or pivot.
As set forth previously, the left and right thumbs are of similar
construction. Thus, it will be appreciated that the inner and outer
shape adaption mechanisms would function similar to the manner that
they function in the left thumb 16 to control the sequence of
pitching or pivoting of the right thumb 18.
With reference now to the engagement of the finger 14 and,
particularly, to the yawing of the finger 14, the finger engagement
sub-assembly 26 includes a finger yaw motor 500 and a finger yaw
gear sub-assembly 502 that cooperate to cause yawing of the finger
14. As depicted in FIG. 3(b), the finger yaw motor 14 has a finger
yaw shaft 504 which is rotatably connected to it and can rotate the
shaft 504 in either a clockwise or counterclockwise direction. It
can be any suitable dc or stepper motor, or any other motor that
can provide the requisite actuation of the finger yaw shaft 504 so
as to drive the finger yaw gear sub-assembly 502. The transverse
axis of the finger yaw shaft 504 is oriented substantially parallel
to the base axis associated with yawing of the finger 14. It is
also oriented substantially perpendicular to the common transverse
axis of the left primary and left common secondary shafts 300 and
302 and to the common transverse axis of the right primary and
right secondary shafts 400 and 402.
The finger yaw gear sub-assembly 502 includes a primary finger yaw
worm gear 506 and a finger bevel gear 508 which are each mounted on
a finger primary drive shaft 510 for rotation with the finger shaft
510. The finger worm gear 506 is located toward one end of the
finger shaft 510 and is engageable with a finger yaw worm 512 that
is mounted for rotation with the finger yaw shaft 504. The bevel
gear 508 is located at the other end of the finger shaft 510 and is
engageable with a suitable finger ring gear 514 or other suitable
gear that can properly engage the bevel gear 508. The transverse
axis of the primary finger shaft 510 is substantially perpendicular
to the finger base axis associated with yawing of the finger 14 and
is substantially parallel to the common transverse axis of the left
primary and left secondary drive shafts 300 and 302. (See e.g.
FIGS. 1-3.) It will also be observed that the primary finger shaft
510, left primary and secondary shafts 300 and 302 and right
primary and secondary shafts are all substantially located in a
common shaft plane.
For the purpose of transferring the rotation of the finger bevel
gear 514 into yawing of the finger 14, the finger ring gear 514 is
mounted on a finger linkage shaft 516 for rotation with the linkage
shaft 516. One end of the linkage shaft 516 is secured to the
finger base 268 for rotation with the finger base 268. The
transverse axis of the finger linkage shaft 516 is substantially
parallel to the finger base axis associated with yawing of the
finger 14 and substantially orthogonal to the transverse axis of
the primary finger shaft 510.
Upon actuation by the finger yaw motor 500, the finger yaw shaft
504 rotates and, thereby, causes the finger yaw worm 512 to engage
the finger yaw worm gear 506 which rotates the primary finger shaft
510. At the same time, the finger bevel gear 508 engages the finger
ring gear 514, thereby rotating the finger linkage shaft 516.
Consequently, the finger 14 yaws in a plane which substantially
orthogonal to the transverse axis of the finger linkage shaft 516
and substantially parallel to the aforementioned common plane. That
is, it yaws about the finger base axis associated with yawing
motion. (See FIGS. 2-3(b).)
The finger yaw gear sub-assembly 502 can also have a finger yaw
housing 518 which surrounds the finger bevel gear 508, ring gear
514 and finger linkage shaft 516. It further defines a side
aperture for receiving the primary finger shaft 510 and a top
aperture (not shown) for receiving the finger linkage shaft 516.
(See FIGS. 3(b) and 13.) The top surface of the housing 518 is
located adjacent to the finger base 268. Suitable upper and lower
bearings 520 and 522 can be situated between the finger yaw housing
518 and the finger linkage shaft 516 in order to stabilize the
shaft 516 during movement of the finger 14. A suitable nut 524 can
also be affixed to the shaft 516 adjacent to the bottom of the
housing 518 in order to maintain the lower bearings 522 in the
housing 518. For a similar purpose, a suitable washer 526 can be
disposed around the finger linkage shaft 516 and located adjacent
to the upper bearings 522. Moreover, the finger linkage shaft 516
can be associated with a suitable key 530 for facilitating torque
transmission between the finger ring gear 514 and the shaft 516.
Thrust or other suitable bearings 532 can also be situated between
the housing 518 and finger base 268.
As best depicted in FIG. 13, the primary finger shaft 510 can also
be surrounded by a primary finger housing 534 and mounted within
suitable bearings 536. The finger yaw shaft 504, finger yaw worm
512 and finger yaw worm gear 506 can also be surrounded by a
housing 538 which is secured to the support structure 28. (See
FIGS. 9 and 13.) As shown in FIG. 13, the finger yaw shaft 504 is
situated within suitable bearings 540. Suitable sleeves 542 and 544
can also be disposed on opposing ends of the finger yaw shaft 504
in order to better retain the bearings 540 between the housing 538
and the shaft 504 and to strengthen the shaft 504. (See FIG. 13.)
For a similar purpose, the portions of the primary finger shaft 510
located near the finger worm gear 506 can be mounted within
suitable bearings 546. The bearings 546 can be retained between the
housing 538 and the finger shaft 510 by suitable sleeves 548 and
550 disposed on opposing sides of the finger worm gear 506. (See
FIG. 9.) Moreover, a suitable key 552 can be associated with finger
shaft 510 to facilitate torque transmission between the finger
shaft 510 and finger yaw worm gear 506.
For the purpose of inducing pivoting or pitching motion of the
finger 14, the finger engagement sub-assembly 26 further includes a
finger pitch motor 554 which actuates a finger tendon or cable 556
through driving a finger pitch gear sub-assembly 558. The finger
pitch motor 554 has a finger pitch shaft 560 which is rotatably
connected to it and can rotate the pitch shaft 560 in either a
clockwise or counterclockwise direction. It can also be surrounded
by a suitable finger pitch motor housing 562. (See e.g. FIG. 1.)
The motor 554 can be any suitable dc or stepper motor or any other
motor that can provide the requisite actuation of the finger pitch
shaft 560 so as to drive the finger pitch sub-assembly 558. The
transverse axis of the finger pitch shaft 560 is oriented
substantially orthogonal to the transverse axis of the finger
primary shaft 510.
The finger pitch gear sub-assembly 558 is constructed essentially
similar to the left pitch gear sub-assembly 366 and has a finger
pitch worm gear 564 which is substantially contiguous with a finger
reducer drum 566. Both the finger pitch Worm gear 564 and finger
reducer drum 566 are mounted for rotation with a finger reducer
shaft 568. The finger worm gear 564 is engageable with a finger
pitch worm 570 that is mounted for rotation on the finger pitch
shaft 560. As such, the finger reducer shaft 568 has its transverse
axis oriented substantially orthogonal to the transverse axis of
the finger pitch shaft 560.
The finger pitch gear sub-assembly 558 can also be provided with
additional features which enhance the stability and operational
characteristics of the finger pitch sub-assembly 558. It,
therefore, can be surrounded by a suitable finger reducer housing
571 which is itself secured to the support structure 28. (See FIGS.
1 and 13.) Since the finger pitch sub-assembly 558 is constructed
essentially similar to the left pitch sub-assembly 366, it will be
observed that it would appear as shown for the left pitch
sub-assembly in FIGS. 9 and 14. Thus, for example, as shown in FIG.
13, the finger linkage shaft 516 has suitable keys 572 and is
associated with suitable upper and lower bearings 574 and 576. The
finger reducer drum 566 and finger pitch worm gear 564 can also be
mounted better for rotation by a suitable screw 577.
The finger tendon 556 is wrapped around the finger reducer drum 566
and connected to the finger 14 in a manner that permits pivoting or
pitching not only of the finger 14 at the inner or base finger
joint but also of the finger phalanges 262, 264 and 266 relative to
each other. More specifically, as shown in FIG. 3(b) the finger
tendon 556 wraps around the finger reducer drum 566 for a plurality
of revolutions in such a way that it forms upper and lower left
leads 578 and 580 that extend from the drum 566 to the finger 16
through bores (not shown) in the finger reducer housing 571. (See
FIGS. 1-3.)
Both leads 578 and 580 pass along the exterior of the hand 10 and
enter the interior of the finger 14 through bores (not shown) in
the finger base linkage 268. (See e.g. FIGS. 1 and 9.) The portion
of the finger tendon 556 that extends between the exterior of the
finger 14 and the finger reducer housing 571 can also be surrounded
by an appropriate casing 582 for preserving the useful life of the
finger tendon 556 (casing only partially shown in FIGS. 9, 13.)
As discussed previously, the particular construction of the finger
engagement sub-assembly 26 that causes pitching or pivoting of the
finger 14 is similar to that described for the left thumb
engagement sub-assembly 22. (Compare FIGS. 3(a) and (b).) The
construction of the finger 14 is similar to that of the left thumb
16. (See FIGS. 4-5.)
Thus, upon actuation by the finger pitch motor 554, the finger
pitch worm 570 engages the finger worm gear 564, thereby causing
the reducer drum 566 to rotate about the transverse axis of the
reducer shaft 568. Since the pitch motor 554 can rotate the pitch
shaft 560 in either a clockwise or counterclockwise direction, the
reducer drum 566 can similarly rotate either clockwise or
counterclockwise. As evident from FIG. 3(b), clockwise rotation of
the reducer drum 566 would apply tension to the upper lead 578.
This would cause the upper lead 578 to tend to wrap further around
the drum 566 and the lower lead 580 to tend to uncoil from it.
Consequently, the finger 14 would be retracted. Relative to the
configuration of the finger 14 shown in FIG. 1, the retraction
would commence at the outer finger phalange 262.
Conversely, when the drum 566 rotates in a counterclockwise
direction, it would apply tension to the lower lead 580. Therefore,
the lower lead 580 would tend to wrap further around the drum 566
while the upper lead 578 would tend to uncoil from it.
Consequently, the finger and its corresponding phalanges 262, 264,
and 266 would pitch or pivot. As set forth previously, the finger
14 and left thumb 16 are constructed similarly. Therefore, it will
be appreciated that the inner and outer shape adaption mechanisms
would function in the finger 14 as previously discussed.
From the foregoing description of the pitching of the left and
right thumbs 16 and 18 and finger 14, it will be observed that the
left and right thumbs can pitch toward and away from each other
substantially in the aforementioned same common shaft plane. Thus,
with reference to FIG. 1, the left and right thumbs 16 and 18 can
roll substantially ninety degrees and then pitch in the
aforementioned shaft plane. Moreover, upon rotating substantially
180 degrees from their respective rest positions shown in FIG. 2,
the thumbs 16 and 18 can yaw in a plane substantially parallel to
the aforementioned shaft plane. The capability of the thumbs 16 and
18 to roll at least substantially 180 degrees permits the hand to
assume a wide variety of configurations. It is somewhat akin to
rotating a human thumb 180 degrees through rotating a human arm a
corresponding amount of degrees. Relative to their respective rest
positions shown in FIG. 2, the finger 14 and thumbs 16 and 18 can
also yaw together in a plane that is substantially parallel to the
aforementioned common shaft plane.
The thumbs 16 and 18 and finger 14 are also advantageously, but not
necessarily, sufficiently spaced apart from each other such that
their respective tips can selectively converge contact each other
when the thumbs 16 and 18 execute a 180 degrees or roll in
combination with suitable pivoting movements of the finger 14 and
thumbs 16 and 18. This provides a significant degree of sensitive
"finger tip" control that is required to properly grasp and
manipulate certain objects such as screw drivers and hypodermic
needles.
In accordance with still another feature of the invention, the
control system 30 (see dotted lines in FIG. 15) selectively
regulates the respective movements of the finger 14 and thumbs 16
and 18. As depicted in FIG. 15, the control system 30 includes a
suitable microcomputer system 600, which is connected by a suitable
communications bus 602 to left thumb, right thumb and finger
interfaces 604, 606 and 608, that interact with suitable sets of
left thumb, right thumb, and finger controllers 610, 612, and 614
respectively.
More particularly, the microcomputer system 600 formulates various
commands or command signals necessary to achieve desired movements
of the finger and thumbs 14, 16 and 18 and electronically transmits
the commands by suitable wiring to the bus 602. The bus 602
differentiates between the commands and electronically routes or
addresses each command by suitable wiring to a separate one of the
interfaces 604, 606 and 608. Thus, for instance, the bus 602 would
differentiate and route a command or command signal directing a
specified or desired movement of the finger 14 to the finger
interface 608. The bus 602 is also advantageously a two-way bus in
that it can accept and assess status information from the
interfaces 604, 606 and 608 on the finger 14 and thumbs 16 and 18
and communicate the status information back to the microcomputer
system 600. Consequently, for example, the bus 602 can notify the
microcomputer system 600 that the finger 14 has jammed or
accomplished its desired movements, or moved a specified
distance.
The set of left thumb controllers 610 has separate left thumb roll,
yaw, and pitch or pivot controllers 616, 618, and 620. Similarly,
the set of right thumb controllers 612 has separate right thumb,
roll, yaw and pitch or pivot controllers 622, 624 and 626, while
the set of finger controllers has separate finger yaw and pitch or
pivot controllers 628 and 630. The interfaces 604, 606 and 608
electronically communicate by suitable wiring with the sets of
controllers 610, 612 and 614 respectively.
That is, each interface 604, 606 and 608, interprets each command
that is addressed to it by the bus 602 and directs the particular
command to a separate one of the aforementioned controllers
contained within the set of controllers 610, 612 and 614 to which
it is linked. Thus, for instance, a particular command interpreted
as directing the finger 14 to yaw would be directed by the finger
interface 608 to the finger yaw controller 628. Conversely, each of
the aforementioned controllers within each set of controllers 610,
612 and 614 can electronically transmit status information back to
its corresponding interface 604, 606, 608 which can then be
electronically transmitted to the bus 602. Thus, for example,
status information that the finger 14 has completed a desired
movement could be transmitted back to the interface 608 and then
transmitted to the bus 602.
The left roll, yaw and pitch controllers 616, 618 and 620
electronically communicate by suitable wiring with the left roll,
yaw and pitch motors 314, 304 and 362 respectively so as to
regulate the rolling, yawing and pitching or pivoting of the left
thumb 16. That is, each controller 616, 618 and 620 processes
appropriate electrical signals from the left interface 604 and
generates suitable control signals that induce an appropriate
voltage for its corresponding motor 314, 304 and 362. The amount of
voltage required for any one of the motors 314, 304 and 362 will
substantially depend upon the dynamics of the left thumb 16, the
particular movement desired for the thumb 16 and the particular
task to be performed.
Similarly, the right roll, yaw and pitch controllers 622, 624 and
626 electronically communicate by suitable wiring with the right
roll, yaw and pitch motors 416, 404 and 458 respectively so as to
regulate the rolling, yawing and pitching or pivoting of the right
thumb 18. Thus, each controller 622, 624 and 626 processes
appropriate electrical signals received from the right thumb
interface 606 and generates suitable control signals that induce an
appropriate voltage for its corresponding motor 416, 404 and
458.
Finally, the finger yaw and pivoting or pitching controllers 628
and 630 electronically communicate with the finger yaw and finger
pitch motors 500 and 554 respectively so as to regulate the yawing
and pitching or pivoting of the finger 14. Therefore, each
controller 628 and 630 processes appropriate electrical signals
received from the finger interface 608 and generate suitable
control signals that induce the appropriate electrical voltage for
its corresponding motor 500 and 554.
It will be appreciated that the particular direction of yawing,
rolling and pitching or pivoting will typically be a function of
whether the particular controller generates a positive or negative
voltage to its corresponding motor. For example, if a positive
voltage were generated in the right roll motor 416 by the right
roll controller 622, the right roll shaft 420 would rotate in a
clockwise direction. Therefore, the right thumb 18 would rotate
counterclockwise as viewed from the frame of reference of an
observer sitting on the sphere 12 and looking toward the hand 10.
On the other hand, if the right controller 622 were to generate a
negative voltage, the right thumb 18 would roll in a
counterclockwise direction. It will further be understood that
various other types of control systems can be employed to regulate
movements of the finger 14 and thumbs 16 and 18.
For the purpose of advantageously being able to monitor and more
readily adjust the movements of the thumbs 16 and 18 and finger 14,
the control system 30 can also be associated with a series of
encoders. More particularly and with reference first to the left
thumb 16, the left thumb engagement sub-assembly 22 can include
left thumb yaw, roll and pitch or pivoting encoders 640, 642 and
644. (See FIGS. 1, 3(c) and 11.) As shown in FIG. 11, the left yaw
encoder 640 has a cylindrical body 645 having a stem 646 which is
received within a bore (not shown) in the left linkage shaft 312
and secured to the shaft by a suitable screw 647. It is also
situated adjacent the left base linkage 40.
The left encoder 640 is further secured to the left thumb roll
housing 320 by a suitable left encoder screw 648 that passes
through a left yaw encoder support plate 650 which itself is
secured to the side 651 of the left roll housing 320 by a suitable
left plate screw 652. (See FIG. 11.) The plate 650 is substantially
L-shaped and is substantially flush with the side 651 of the
housing 320 and with the bottom of the body 645 of the encoder 640.
It also but defines an aperture for permitting the stem 646 to pass
through to the bore of the left linkage shaft 312. Consequently,
the body 645 of the left yaw encoder 640 will remain substantially
stationary during yawing of the thumb 16, while its stem 646 will
rotate with the shaft 312. Thus, the encoder 640 will substantially
detect the degree of yawing of the thumb 16 by sensing the degree
of rotation or change in angular position of the left linkage shaft
312. (See FIGS. 3(c) and 11.)
As depicted in FIG. 15, the left yaw encoder 640 then generates a
digit status signal indicative of the yaw movement of the left
thumb 16 and electrically transmits the signal by suitable wiring
back to the left yaw controller 618. The left yaw controller 618
then compares this information with the command signal from the
left interface 604 relating to the desired yaw position of the left
thumb 16. If this comparison reflects that the thumb 16 has not yet
achieved its desired yaw position, the controller 618 then
generates a control signal which adjusts the voltage in the left
yaw motor 304 so that the desired yaw position can be obtained. On
the other hand, if this comparison reflects that the thumb 16 has
attained its desired position, the controller 618 can either shut
off the motor 304 or reduce the voltage in the motor 304 to a level
at which it will not actuate the thumb 16. At the same time, the
controller 618 can send appropriate status information relating to
the yaw movement of the thumb 16 back to the interface 604. The
status information will then proceed to the microcomputer system
600 via bus 602.
The left roll encoder 642 similarly has a cylindrical body 656
having a stem (not shown) which is secured within the left roll
shaft 318 of the left roll motor 314. (See FIG. 3(c).) For that
purpose, the left roll shaft 318 is preferably further elongated
such that it extends through the rear of the left roll motor
housing 319. (See FIGS. 1 and 3(c).) As shown in FIG. 1, the left
roll encoder 642 is secured to the left roll motor housing 319 by a
suitable support plate 658 that is itself secured to the housing
319. The plate 658 is again substantially L-shaped and is
substantially flush with the housing 319 and the top of the body
656 of encoder 642. Consequently, the body 656 of the encoder 642
will remain substantially stationary, while its stem will rotate
with the left roll shaft 318. In like manner to the left yaw
encoder 640, the left roll encoder 642 substantially detects the
degree of rolling of the thumb 16 by sensing the degree of rotation
or changes in angular position of the left roll shaft 318.
As depicted in FIG. 15, the left roll encoder 642 then generates a
digit status signal indicative of the roll movement of the left
thumb 16 and electronically transmits the signal by suitable wiring
to the left roll controller 616. The controller 616 then compares
this information with the command signal from the interface 604
relating to the desired roll position of the left thumb 16. If
appropriate, it then adjusts, or reduces the voltage in the left
roll motor 314 or shuts off the motor 314 in a manner similar to
that of the left yaw controller 618. At the same time, the
controller 616 can send information relating to the rolling of the
thumb 16 back to the microcomputer system 600 in the same manner as
performed by the left yaw controller 618. (See FIG. 15.)
As shown in FIG. 14, the left pitch or pivot encoder 644 has a
cylindrical body 660 having a stem 662 which is secured within a
bore (not shown) within the left reducer shaft 376. The body 660 of
the encoder 644 is secured to the left reducer housing 380 by a
suitable support plate 664. (See FIGS. 1, 3(c) and 14.) As such,
the stem 662 is rotatable with the shaft 376, while the body 660 of
the encoder 644 remains substantially stationary. In like manner to
the left yaw encoder 640, the left pitch encoder 644 substantially
detects the degree of pitching of the thumb 16 by sensing the
degree of rotation or change in angular position of the left
reducer shaft 376.
As depicted in FIG. 15, it then generates a digit status signal
indicative of the pitching or pivoting movement of the left thumb
16 and electronically transmits the signal to the left pitch
controller 620 by suitable wiring. Thereafter, the controller 620
compares this information with the command signal from the
interface 604 relating to the desired pitch position of the thumb
16. If appropriate, it then adjust or reduces the voltage in the
left pitch motor 362 or shuts off the motor 362 in a manner similar
to that for the left yaw controller 618. At the same time, the
controller 620 can send status information relating to the pitching
of the left thumb 16 back to the microcomputer system 600 in a
manner similar to that of the left yaw controller 618.
It will be understood that the encoders 640, 642 and 644 can be
positioned in other ways as well, for example, the encoders 640 and
644 could appropriately be connected to the left yaw and pitch
motor housings 307 and 370. In that event, their respective stems
646 and 662 would be secured to the left primary shaft 300 and left
pitch shaft 368 respectively.
Referring next to the right thumb 18, the right thumb engagement
sub-assembly 24 can include right thumb yaw, roll and pitch or
pivot encoders 665, 668 and 670. (See FIGS. 2, 3(a) and 14.) As
shown in FIG. 15, the right yaw encoder 665 has a cylindrical body
672 having a stem 674 which is received within a bore (not shown)
in the right linkage shaft 414 and secured to the shaft 414 by a
suitable screw 676. It is also situated adjacent the right thumb
base or base linkage 244.
The right yaw encoder 665 is further secured to the right thumb
roll housing 424 by a suitable right encoder screw 678. The screw
678 passes through a right yaw encoder support plate 680 which
itself is secured to the right roll housing 424 by a suitable right
plate screw 682. The plate 680 is substantially L-shaped and is
substantially flush with the bottom of the body 672 of the encoder
665. It also defines an aperture for permitting the stem 674 to
pass through to the bore of the right linkage shaft 414.
Consequently, the body 672 of the right yaw encoder 665 will remain
substantially stationary during yawing of the thumb 18, while its
stem 674 will rotate with the shaft 414. Thus, the encoder 665 will
substantially detect the degree of pitching of the thumb 18 by
sensing the degree of rotation or change in angular position of the
right linkage shaft 414. (See FIGS. 3(a) and 14.)
The right yaw, roll and pitch encoders 665, 668 and 670 are
constructed and function similarly to their counterpart left, yaw,
roll and pitch encoders 640, 642 and 644. (Compare, for example,
FIGS. 3(a) and (c).) More particularly, as depicted in FIG. 15, the
right yaw encoder 665 generates a digit status signal indicative of
the movement of the right thumb 16 and electrically transmits the
signal by suitable wiring back to the right yaw controller 624. The
right yaw controller 624 then compares this information with the
command signal from the interface 606 relating to the desired yaW
position of the right thumb 18. If this comparison reflects that
the thumb 18 has not yet achieved its desired yaw position, the
controller 624 then generates a control signal which adjusts the
voltage in the right yaw motor 404 so that the desired position can
be obtained.
On the other hand, if this comparison reflects that the thumb 18
has attained its desired position, the controller 624 can either
shut off the motor 404 or reduce the voltage in the motor 404 to a
level at which it will not actuate the thumb 18. At the same time,
the controller 624 can send appropriate status information relating
to the yaw movement of the thumb 18 back to the interface 606. The
status information will then proceed to the microcomputer system
600 via bus 602.
The right roll encoder 668 similarly has a cylindrical body 684
having a stem (not shown) which is secured within the right roll
shaft 420 of the right roll motor 416. (See FIG. 3(a).) For that
purpose, the right roll shaft 420 is preferably further elongated
such that it extends through the rear of the right roll motor
housing 422. (See FIG. 2 and 3(a).) As shown in FIG. 2, the right
roll encoder 668 is secured to the right roll motor housing 422 by
a suitable support plate 686 that is itself secured to the housing
422. The plate 686 is again substantially L-shaped and is
substantially contiguous with the bottom of the body 684 of the
encoder 668. Consequently, the body 684 of the encoder 668 will
remain substantially stationary, while its stem will rotate with
the right roll shaft 420. In like manner to the right yaw encoder
665 the right roll encoder 668 substantially detects the degree of
rolling of the thumb 18 by sensing the degree of rotation or
changes in position of the right roll shaft 420.
As depicted in FIG. 15, the right roll encoder 668 then generates a
digit status signal indicative of the roll movement of the right
thumb 18 and electronically transmits the signal by suitable wiring
to the right roll controller 622. The controller 622 then compares
this information with the command signal from the interface 606
relating to the desired roll position of the right thumb 18. If
appropriate, it then adjusts, or reduces the voltage in the right
roll motor 416 or shuts off the motor 416 in a manner similar to
that of the right yaw controller 624. At the same time, the
controller 622 can send information relating to the rolling of the
thumb 18 back to the microcomputer system 600 in the same manner as
performed by the right yaw controller 624. (See FIG. 15.)
As shown in FIG. 3(a) and partially shown in FIG. 11, the right
pitch or pivot encoder 670 has a cylindrical body 688 having a stem
690 which is secured within a bore (not shown) within the right
reducer shaft 472. The body 688 of the encoder 670 is secured to
the right reducer housing 476 by a suitable support plate 692. (See
FIG. 11.) As such, the stem 690 is rotatable with the shaft 472,
while the body 688 of the encoder 670 remains substantially
stationary. In like manner to the right yaw encoder 665, the right
pitch encoder 670 substantially detects the degree of pitching of
the thumb 18 by sensing the degree of rotation of the right reducer
shaft 472.
As depicted in FIG. 15, it then generates a digit status signal
indicative of the pitch or pivot movement of the right thumb 18 and
electronically transmits the signal to the right pitch controller
626 by suitable wiring. Thereafter, the controller 626 compares
this information with the command signal from the interface 604
relating to the desired pitch position of the thumb 18. If
appropriate, it then adjust or reduces the voltage in the right
pitch motor 458 or shuts off the motor 458 in a manner similar to
that for the right yaw encoder 665. At the same time, the
controller 626 can send status information relating to the pitching
of the right thumb 18 back to the microcomputer system 600 in a
manner similar to that of the right yaw controller 622.
Referring next to the finger 14, the finger engagement sub-assembly
26 can include finger yaw and pitch or pivot encoders 694 and 696.
(See FIGS. 1-2, 3(b) and 13.) As shown in FIGS. 3(b) and 13, the
finger yaw encoder 694 has a cylindrical body 698 having a stem 700
which is received within a bore (not shown) in the bottom of the
finger linkage shaft 516 and secured to the shaft 516 by a suitable
screw 702. The finger encoder 694 is further secured to the finger
yaw housing 518 by a finger yaw encoder support plate 704 which
itself is secured to the bottom of the finger yaw housing 518. The
plate 704 is substantially L-shaped and is substantially flush with
the bottom of the body 698 of the encoder 694. It also defines an
aperture for permitting the stem 700 to pass through into the bore
of the finger linkage shaft 516. Consequently, the body 698 of the
finger yaw encoder 694 will remain substantially stationary during
yawing of the finger 14, while its stem 700 will rotate with the
shaft 516. Thus, the encoder 694 will substantially detect the
degree of yawing of the finger 14 by sensing the degree of rotation
or change in angular position of the finger linkage shaft 516. (See
FIGS. 3(c) and 13.) It will be observed that, there is preferably
some space clearance between the bottom of the finger linkage shaft
516 and the support plate 704. Similar spaces also preferably exist
with respect to the left and right thumb yaw encoders 640 and 665.
(See FIGS. 11 and 14.)
The finger yaw encoder 694 is constructed and, functions similarly
to, its counterpart left yaw encoder 640, except that the finger
yaw encoder 694 is oriented somewhat differently. (Compare FIGS.
3(b) and (c).) More particularly, as depicted in FIG. 15, the
finger yaw encoder 694 generates a digit status signal indicative
of the yaw movement of the finger 14 and electrically transmits the
signal by suitable wiring to the finger yaw controller 628. The
finger yaw controller 628 then compares this information with the
command signal from the interface 608 relating to the desired yaw
position of the finger 14. If this comparison reflects that the
finger 14 has not yet achieved its desired yaw position, the
controller 628 then adjusts the voltage in the finger yaw motor 500
so that the desired position can be obtained.
On the other hand, if this comparison reflects that the finger 14
has attained its desired position, the controller 628 can either
shut off the motor 500 or reduce the voltage in the motor 500 to a
level at which it will not actuate the finger 14. At the same time,
the controller 628 can send appropriate status information relating
to the yaw movement of the finger 14 back to the interface 608. The
status information will then proceed to the microcomputer system
600 via bus 602.
The finger pitch or pivot encoder 696 is constructed and oriented
similar to the left and right pitch encoders 644 and 670. As shown
in FIG. 1, 3(b) and 13, the finger pitch encoder 696 has a
cylindrical body 706 having a stem 708 which is secured within a
bore (not shown) within the finger reducer shaft 568. As such, the
stem 708 is rotatable with the shaft 568, while the body 706 of the
encoder 696 remains substantially stationary. The body 706 of the
encoder 696 is secured to the finger reducer housing 571 by a
suitable support plate 710. In like manner to the left pitch
encoder 644, the finger pitch encoder 696 substantially detects the
degree of pitching or pivoting of the finger 14 by sensing the
degree of rotation of the finger reducer shaft 568.
As depicted in FIG. 15, it then generates a digit status signal
indicative of the pitch or pivot movement of the finger 14 and
electronically transmits appropriate movement information to the
finger pitch controller 630 by suitable wiring. Thereafter, the
controller 630 compares this information with the command signal
from the interface 608 relating to the desired pitch position of
the finger 14. If appropriate, it then adjust or reduces the
voltage in the finger pitch motor 554 or shuts off the motor 554 in
a manner similar to that for the left pitch encoder 644. At the
same time, the controller 630 can send status information relating
to the pitching of the finger 14 back to the microcomputer system
600 in a manner similar to that of the left pitch controller
620.
It will be understood that various other forms of control systems
can be fashioned in accordance with the present invention. Further,
the control system 30 can of course selectively cause the finger 14
and thumbs 16 and 18 to engage in specified movements substantially
in unison.
An alternative embodiment of a shape adaption mechanism associated
with the present invention is shown in FIG. 6. This embodiment has
a shape adaption mechanism 722 and is similar in all respects to
the embodiments of the inner and outer shape adaption mechanisms
130 and 132 discussed above (see FIGS. 4-5), with one exception.
That is, it replaces the inner and outer friction plates 180 and
230 respective of the previous embodiment with a bellville or
substantially dish-shaped washer 724 (see FIG. 6.) Consequently, it
also does not, for example, have the hollow friction stem 182 or
secondary brake pin 184 associated with the friction plate 180.
For simplicity, FIG. 6 depicts how the washer 724 would appear in
the inner shape adaption mechanism 130 upon its supplanting the
inner friction plate 230. In all other respects, however, the shape
adaption mechanism 722 of this embodiment functions similarly to
the inner and outer shape adaption mechanisms 130 and 132. The
washer 724 has the same function as the inner and outer friction
plates 180 and 230. Thus, it would move along the inner brake rod
138 upon application of sufficient force to the inner arm roller
164. Conversely, it would return to its equilibrium position when
the force has sufficiently subsided. The resiliency of the washer
722 also tends to prevent it from undesirably locking with the
inner brake pulley 134.
It will be understood that the above-described alternative
embodiment can be situated between the various joints of the right
thumb 18 and the finger 14 in the manner discussed in connection
with the outer and inner shape adaption mechanisms 132 and 130 of
the previous embodiment. Moreover, the particular type of biasing
elements and other components chosen will again substantially
depend upon the dynamics of the thumbs 16 and 18 and finger 14 and
the particular tasks to be accomplished.
Still another alternative embodiment of a shape adaption mechanism
associated with the present invention is shown in FIGS. 7-8. In
this embodiment, inner and outer shape adaption mechanisms 730 and
732 are employed in place of the inner and outer shape adaption
mechanisms 130 and 132 of the embodiment of FIGS. 4-5. The
mechanisms 730 and 732, however, function essentially similar to
the shape adaption mechanisms of the previously described
embodiments in that they permit the same controlled sequential
pitch or pivoting. More particularly, and with exemplary reference
to the left thumb 16, the inner shape adaption mechanism 730 is
situated between the middle and inner or base left thumb joints 76
and 78. (See FIG. 8.) It includes an inner left brake pulley 734
which is disposed around an inner left brake rod 736 and which has
an outer convex surface 738 that is engageable with an inner left
brake 740. (See FIGS. 7-8.)
The inner brake pulley 734 is selectively rotatable relative to the
inner brake rod 736 and is constructed similarly to the inner brake
rod 138 of the first embodiment. (See FIGS. 4-5 and 8.) It does
not, however, have a friction pad 144 affixed to its inner radial
surface 742. The inner brake rod 736 is secured to the opposing
side linkages 56 and 58 of the inner left phalange 38. It is also
constructed similar to the inner brake rod 138 of the first
embodiment, except that it need not necessarily have external inner
rod threads 150.
The inner left brake 740 includes an elongated inner brake arm 744
which is pivotally secured on one end to a secondary inner brake
rod 746 and on the other end has an inner arm rod 748 connected to
it. The transverse axis of the inner brake arm 744 is substantially
perpendicular to the transverse axis of the inner brake rod 736.
The inner brake arm 744 is also situated above the top of the outer
surface 738 of inner brake pulley 734. (See FIGS. 7-8.) The
secondary inner brake rod 746 is secured to the side linkage 56 of
the inner left phalange 38 and has its transverse axis oriented
substantially parallel to the transverse axis of the inner brake
rod 736. The inner arm rod 748 has an inner arm roller 750 disposed
around it. As such, the common transverse axis of the inner arm rod
748 and the inner arm roller 750 is oriented substantially parallel
to the transverse axis of the inner brake rod 736.
For the purpose of applying braking force to the inner brake pulley
734, the inner brake 740 further includes an inner brake member 752
secured to the intermediate section of the inner brake arm 744. The
member 752 has a substantially rectangular base 753 having a
concave outer surface 754 that substantially conforms to the outer
surface 738 of the inner brake pulley 734. As shown in FIGS. 7-8,
the inner brake member 752 also has two opposing somewhat bell
shaped sides 755 and 756 that rise from the rectangular base 753
and slant inward toward the inner brake arm 744. They are then
secured to the intermediate section of the inner brake arm 744 by a
suitable pin 758. The concave outer surface 754 of the inner brake
member 752 can also be provided with a suitable friction pad 760.
The pad 760 conforms to the concave surface 754 and the outer
surface 738 and is abutable with the outer surface 738 of the inner
brake pulley 734.
For the purpose of more selectively and effectively regulating the
braking force exerted by the inner brake 740, the inner left brake
740 also advantageously includes a suitable biasing element 762,
which can be a suitable helical spring. The biasing element 762 has
one of its ends secured to the inner arm rod 748, while its other
end is secured to the side linkage 58 of the inner left phalange
38.
As depicted in FIG. 8, the equilibrium or rest position of the
inner brake 740 corresponds to the position in which the left thumb
16 is fully extended. In this equilibrium position, therefore, the
biasing element 762 exerts a threshold initial tensile or pulling
force on the inner brake arm 744. This in turn provides the inner
brake member 752 with a threshold braking force that is initially
exerted on the outer surface 738 of the inner brake pulley 734.
However, when sufficient force becomes incident on the inner arm
roller 750, the inner brake member 752 will move downward.
Consequently, the braking force against the inner brake pulley 734
will augment above its threshold level and, thereby, further resist
clockwise rotation of the inner brake pulley 734.
Conversely, when the force on the inner arm roller 750 has
sufficiently subsided, the biasing element 762 will return the
inner brake 740 to its equilibrium position. It will also be
observed that the inner brake 740 can be associated with an inner
tendon brake pin 764 and suitable screw pin 766 in a fashion
similar to inner tendon brake pin 170 and screw pin 174 of the
inner brake 136. (See FIG. 7.)
The outer shape adaption mechanism 732 is constructed essentially
similar to, and functions essentially alike, the inner shaped
adaption mechanism 730. More particularly, as depicted in FIG. 8,
the outer shape adaption mechanism 732 is situated between the
outer and middle left thumb joints 74 and 76. It includes an outer
left brake pulley 768 which is disposed around an outer left brake
rod 770 and which has an outer convex surface 772 which is
engageable with an outer left brake 774.
The outer brake pulley 768 is selectively rotatable relative to the
outer brake rod 770 and is constructed similarly to the outer brake
rod 190 of the first embodiment. (See FIG. 4-5 and 8.) It does not,
however, have a friction pad 196 affixed to its inner radial
surface 776. The outer brake rod 770 is secured to the opposing
side linkages 52 and 54 of the middle left phalange 36. It is also
constructed similarly to the outer brake rod 190 of the first
embodiment, except that it need not necessarily have external outer
rod threads 202.
The outer left brake 774 includes an elongated outer brake arm 778
which is pivotally secured to one end of a secondary outer brake
rod 780 and on the other end has an outer arm rod 782 connected to
it. The transverse axis of the outer brake arm 778 is substantially
perpendicular to the transverse axis of the outer brake rod 770.
The outer brake arm 778 is also situated above the top of the outer
surface 772 of the outer brake pulley 768. (See FIG. 8.)
The secondary outer brake rod 780 is secured to the side linkage 52
of the middle left phalange 36 and has its transverse axis oriented
substantially parallel to the transverse axis of the outer brake
rod 770. The outer arm rod 782 has an outer arm roller 784
preferably rotatably disposed around it. As such, the common
transverse axis of the outer arm rod 782 and the outer arm roller
784 is oriented substantially parallel to the transverse axis of
the outer brake rod 770.
For the purpose of applying braking force to the outer brake pulley
768, the outer brake 774 further includes an outer brake member
786. The member 786 is secured to the intermediate section of the
outer brake arm 778 and is configured similar to the inner brake
member 752. (See FIG. 8.) As such, it has a similar rectangular
base 788 having a similar concave surface 790 and similar bell
shaped sides 792 and 794. Moreover, the outer brake member 786 can
also have a suitable friction pad 796. The pad 796 similarly
conforms to the concave surface 790 and the outer surface 772 and
is abutable with the outer surface 772 of the outer brake pulley
768.
In like manner to the inner brake 740, the outer brake 774 also
advantageously includes a suitable biasing element 798, which can
be a suitable helical spring. The biasing element 798 has one of
its ends secured to the outer arm rod 782, while its other end is
secured to the side linkage 54 of the middle left phalange 36.
Thus, the biasing element 798 exerts a threshold initial force on
the outer brake arm 778. This provides the outer brake member 786
with a threshold braking force that is initially exerted on the
outer surface 772 of the outer brake pulley 768.
However, when sufficient force incident on the outer arm roller
784, the outer brake member 786 will move downward. Consequently,
the outer brake member 786 will apply increasing braking force
against the outer brake pulley 768. The outer brake pulley 768
will, therefore, be increasingly restrained from rotating clockwise
relative to the outer brake rod 770. Conversely, when the force on
the outer arm roller 784 has sufficiently subsided, the biasing
element 798 will return the outer brake 774 to its equilibrium
position. Like the inner brake 740, the outer brake 774 can also be
associated with an outer tendon brake pin and a suitable screw pin
for the reason previously explained.
It will be observed that the left thumb tendon 364 wraps around the
inner and outer shape adaption mechanisms 730 and 732 somewhat
differently than it wraps around the shape adaption mechanisms of
the previous embodiments. That is, while the lower lead 396 of the
left tendon 364 wraps similarly, the upper lead 395 is received by
the respective undersides of the inner and outer brake pulleys 734
and 768. (See FIG. 8.) In contrast, the upper lead 395 does not
contact the shape adaption mechanisms of the previous embodiments.
(See FIG. 5.) It will also be appreciated that various other forms
of shape adaption mechanisms that apply braking force so as to
enhance the stability and control the pitching or pivoting of the
left thumb, right thumb and fingers 16, 18 and 14 can be
constructed in accordance with the present invention.
The inner and outer shape adaption mechanisms 730 and 732 cooperate
to control the pitching or pivoting sequence of the finger 14 and
left and right thumbs 16 and 18 in essentially the same manner as
that described for the inner and outer shape adaption mechanisms
130 and 132 of the first embodiment. Thus, for instance, in a case
similar to the first exemplary situation described above, tensile
force would propagate along the lower lead 396 and cause a downward
force to become incident on the inner arm roller 750. This tensile
force would initially be counteracted by the threshold braking
force exerted by the inner brake member 752 on the outer surface
738 of the inner brake pulley 734.
If the tensile force is sufficient to cause the inner arm roller
750 to move downward, then the inner brake member 752 will
correspondingly move downward. As a result, the braking force
exerted on the outer surface 738 will increase and, thereby,
further restrain clockwise rotation of the inner brake pulley 734.
Moreover, the increase in braking force will prevent the
propagation of sufficient tensile force to accomplish pivoting or
pitching of the outer, middle and inner left phalanges 34, 36 and
38 relative to each other. At the same time, the left phalanges 34,
36 and 38 as a whole will together pivot or pitch relative to the
left thumb base 40, because the braking force exceeds the tensile
force.
By way of further example, in a situation akin to the second
situation described above, the tensile force would continue to
increase until it superceded the maximum augmented braking force.
The inner brake 734 would then rotate clockwise and eventually
sufficient tensile force would propagate to the middle left pulley
94. This would cause the middle left phalange 36 to pivot or pitch
downward relative to the inner left phalange 38. The middle left
phalange 36 will then continue to pivot or pitch downward until an
object obstructs its further movement.
The left pitch motor 362 would then provide increasing tensile
force to the lower lead 396 so as to counteract the force exerted
by the object in the area between the outer and middle left joints
74 and 76. This increasing tensile force would then propagate to
the outer shape adaption mechanism 732. The mechanism 732 would
then function similarly to the mechanism 730. Eventually, the
increasing tensile force would supercede the maximum augmented
braking force supplied by the outer brake 774. Consequently,
sufficient tensile force would propagate to the outer left pulley
80. The outer left phalange 34 would then pitch or pivot relative
to the middle left phalange 36 until the outer left phalange 34
contacted the object.
It will therefore again be appreciated that the above-described
controlled sequential pivoting or pitching of the phalanges 34, 36
and 38 will result in the left thumb 16 versatilely and stably
configuring itself so as to properly grip and, thereafter,
manipulate the object. It will further be understood that the inner
and outer shape adaption mechanisms 730 and 732 would function
similarly for the finger 14 and right thumb 18.
Although the invention has been described in detail with reference
to the presently preferred embodiments, it will be appreciated by
those skilled in the art that various modifications can be made
without departing from the spirit or scope of the invention.
Accordingly, the scope of present invention is not to be limited by
the particular embodiments above but is to be defined only by the
claims set forth below and equivalents thereof.
* * * * *